libguestfs/daemon/tar.c

/* libguestfs - the guestfsd daemon
 * Copyright (C) 2009 Red Hat 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 of the License, 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., 675 Mass Ave, Cambridge, MA 02139, USA.
 */

#include <config.h>

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <fcntl.h>

#include "../src/guestfs_protocol.h"
#include "daemon.h"
#include "actions.h"

static int
fwrite_cb (void *fp_ptr, const void *buf, int len)
{
  FILE *fp = *(FILE **)fp_ptr;
  return fwrite (buf, len, 1, fp) == 1 ? 0 : -1;
}

/* Has one FileIn parameter. */
int
do_tar_in (char *dir)
{
  int err, r, len;
  FILE *fp;
  char *cmd;

  if (!root_mounted || dir[0] != '/') {
    cancel_receive ();
    reply_with_error ("tar-in: root must be mounted and path must be absolute");
    return -1;
  }

  /* "tar -C /sysroot%s -xf -" but we have to quote the dir. */
  len = 2 * strlen (dir) + 32;
  cmd = malloc (len);
  if (!cmd) {
    err = errno;
    cancel_receive ();
    errno = err;
    reply_with_perror ("malloc");
    return -1;
  }
  strcpy (cmd, "tar -C /sysroot");
  shell_quote (cmd+15, len-15, dir);
  strcat (cmd, " -xf -");

  fp = popen (cmd, "w");
  if (fp == NULL) {
    err = errno;
    cancel_receive ();
    errno = err;
    reply_with_perror ("%s", cmd);
    free (cmd);
    return -1;
  }
  free (cmd);

  r = receive_file (fwrite_cb, &fp);
  if (r == -1) {		/* write error */
    err = errno;
    cancel_receive ();
    errno = err;
    reply_with_perror ("write: %s", dir);
    pclose (fp);
    return -1;
  }
  if (r == -2) {		/* cancellation from library */
    pclose (fp);
    /* Do NOT send any error. */
    return -1;
  }

  if (pclose (fp) == -1) {
    err = errno;
    cancel_receive ();
    errno = err;
    reply_with_perror ("pclose: %s", dir);
    return -1;
  }

  return 0;
}

/* Has one FileOut parameter. */
int
do_tar_out (char *dir)
{
  int r, len;
  FILE *fp;
  char *cmd;
  char buf[GUESTFS_MAX_CHUNK_SIZE];

  NEED_ROOT (-1);
  ABS_PATH (dir, -1);

  /* "tar -C /sysroot%s -cf - ." but we have to quote the dir. */
  len = 2 * strlen (dir) + 32;
  cmd = malloc (len);
  if (!cmd) {
    reply_with_perror ("malloc");
    return -1;
  }
  strcpy (cmd, "tar -C /sysroot");
  shell_quote (cmd+15, len-15, dir);
  strcat (cmd, " -cf - .");

  fp = popen (cmd, "r");
  if (fp == NULL) {
    reply_with_perror ("%s", cmd);
    free (cmd);
    return -1;
  }
  free (cmd);

  /* Now we must send the reply message, before the file contents.  After
   * this there is no opportunity in the protocol to send any error
   * message back.  Instead we can only cancel the transfer.
   */
  reply (NULL, NULL);

  while ((r = fread (buf, 1, sizeof buf, fp)) > 0) {
    if (send_file_write (buf, r) < 0) {
      pclose (fp);
      return -1;
    }
  }

  if (ferror (fp)) {
    perror (dir);
    send_file_end (1);		/* Cancel. */
    pclose (fp);
    return -1;
  }

  if (pclose (fp) == -1) {
    perror (dir);
    send_file_end (1);		/* Cancel. */
    return -1;
  }

  send_file_end (0);		/* Normal end of file. */
  return 0;
}

/* Has one FileIn parameter. */
int
do_tgz_in (char *dir)
{
  int err, r, len;
  FILE *fp;
  char *cmd;

  if (!root_mounted || dir[0] != '/') {
    cancel_receive ();
    reply_with_error ("tar-in: root must be mounted and path must be absolute");
    return -1;
  }

  /* "tar -C /sysroot%s -zxf -" but we have to quote the dir. */
  len = 2 * strlen (dir) + 32;
  cmd = malloc (len);
  if (!cmd) {
    err = errno;
    cancel_receive ();
    errno = err;
    reply_with_perror ("malloc");
    return -1;
  }
  strcpy (cmd, "tar -C /sysroot");
  shell_quote (cmd+15, len-15, dir);
  strcat (cmd, " -zxf -");

  fp = popen (cmd, "w");
  if (fp == NULL) {
    err = errno;
    cancel_receive ();
    errno = err;
    reply_with_perror ("%s", cmd);
    free (cmd);
    return -1;
  }
  free (cmd);

  r = receive_file (fwrite_cb, &fp);
  if (r == -1) {		/* write error */
    err = errno;
    cancel_receive ();
    errno = err;
    reply_with_perror ("write: %s", dir);
    pclose (fp);
    return -1;
  }
  if (r == -2) {		/* cancellation from library */
    pclose (fp);
    /* Do NOT send any error. */
    return -1;
  }

  if (pclose (fp) == -1) {
    err = errno;
    cancel_receive ();
    errno = err;
    reply_with_perror ("pclose: %s", dir);
    return -1;
  }

  return 0;
}

/* Has one FileOut parameter. */
int
do_tgz_out (char *dir)
{
  int r, len;
  FILE *fp;
  char *cmd;
  char buf[GUESTFS_MAX_CHUNK_SIZE];

  NEED_ROOT (-1);
  ABS_PATH (dir, -1);

  /* "tar -C /sysroot%s -zcf - ." but we have to quote the dir. */
  len = 2 * strlen (dir) + 32;
  cmd = malloc (len);
  if (!cmd) {
    reply_with_perror ("malloc");
    return -1;
  }
  strcpy (cmd, "tar -C /sysroot");
  shell_quote (cmd+15, len-15, dir);
  strcat (cmd, " -zcf - .");

  fp = popen (cmd, "r");
  if (fp == NULL) {
    reply_with_perror ("%s", cmd);
    free (cmd);
    return -1;
  }
  free (cmd);

  /* Now we must send the reply message, before the file contents.  After
   * this there is no opportunity in the protocol to send any error
   * message back.  Instead we can only cancel the transfer.
   */
  reply (NULL, NULL);

  while ((r = fread (buf, 1, sizeof buf, fp)) > 0) {
    if (send_file_write (buf, r) < 0) {
      pclose (fp);
      return -1;
    }
  }

  if (ferror (fp)) {
    perror (dir);
    send_file_end (1);		/* Cancel. */
    pclose (fp);
    return -1;
  }

  if (pclose (fp) == -1) {
    perror (dir);
    send_file_end (1);		/* Cancel. */
    return -1;
  }

  send_file_end (0);		/* Normal end of file. */
  return 0;
}