postlogin.c

文件传输协议linux 下vsftpd2.1.0.tar.gz

  if (p_raw == 0)
  {
    vsf_cmdio_write(p_sess, FTP_BADCMD, "Illegal PORT command.");
    return;
  }
  the_port = vals[4] << 8;
  the_port |= vals[5];
  vsf_sysutil_sockaddr_clone(&p_sess->p_port_sockaddr, p_sess->p_local_addr);
  vsf_sysutil_sockaddr_set_ipv4addr(p_sess->p_port_sockaddr, vals);
  vsf_sysutil_sockaddr_set_port(p_sess->p_port_sockaddr, the_port);
  /* SECURITY:
   * 1) Reject requests not connecting to the control socket IP
   * 2) Reject connects to privileged ports
   */
  if (!tunable_port_promiscuous)
  {
    if (!vsf_sysutil_sockaddr_addr_equal(p_sess->p_remote_addr,
                                         p_sess->p_port_sockaddr) ||
        vsf_sysutil_is_port_reserved(the_port))
    {
      vsf_cmdio_write(p_sess, FTP_BADCMD, "Illegal PORT command.");
      port_cleanup(p_sess);
      return;
    }
  }
  vsf_cmdio_write(p_sess, FTP_PORTOK,
                  "PORT command successful. Consider using PASV.");
}

static void
handle_stor(struct vsf_session* p_sess)
{
  handle_upload_common(p_sess, 0, 0);
}

static void
handle_upload_common(struct vsf_session* p_sess, int is_append, int is_unique)
{
  static struct vsf_sysutil_statbuf* s_p_statbuf;
  static struct mystr s_filename;
  struct mystr* p_filename;
  struct vsf_transfer_ret trans_ret;
  int new_file_fd;
  int remote_fd;
  int success = 0;
  int created = 0;
  int do_truncate = 0;
  filesize_t offset = p_sess->restart_pos;
  p_sess->restart_pos = 0;
  if (!data_transfer_checks_ok(p_sess))
  {
    return;
  }
  resolve_tilde(&p_sess->ftp_arg_str, p_sess);
  p_filename = &p_sess->ftp_arg_str;
  if (is_unique)
  {
    get_unique_filename(&s_filename, p_filename);
    p_filename = &s_filename;
  }
  vsf_log_start_entry(p_sess, kVSFLogEntryUpload);
  str_copy(&p_sess->log_str, &p_sess->ftp_arg_str);
  prepend_path_to_filename(&p_sess->log_str);
  if (!vsf_access_check_file(p_filename))
  {
    vsf_cmdio_write(p_sess, FTP_NOPERM, "Permission denied.");
    return;
  }
  /* NOTE - actual file permissions will be governed by the tunable umask */
  /* XXX - do we care about race between create and chown() of anonymous
   * upload?
   */
  if (is_unique || (p_sess->is_anonymous && !tunable_anon_other_write_enable))
  {
    new_file_fd = str_create(p_filename);
  }
  else
  {
    /* For non-anonymous, allow open() to overwrite or append existing files */
    new_file_fd = str_create_append(p_filename);
    if (!is_append && offset == 0)
    {
      do_truncate = 1;
    }
  }
  if (vsf_sysutil_retval_is_error(new_file_fd))
  {
    vsf_cmdio_write(p_sess, FTP_UPLOADFAIL, "Could not create file.");
    return;
  }
  created = 1;
  vsf_sysutil_fstat(new_file_fd, &s_p_statbuf);
  if (vsf_sysutil_statbuf_is_regfile(s_p_statbuf))
  {
    /* Now deactive O_NONBLOCK, otherwise we have a problem on DMAPI filesystems
     * such as XFS DMAPI.
     */
    vsf_sysutil_deactivate_noblock(new_file_fd);
  }
  /* Are we required to chown() this file for security? */
  if (p_sess->is_anonymous && tunable_chown_uploads)
  {
    vsf_sysutil_fchmod(new_file_fd, tunable_chown_upload_mode);
    if (tunable_one_process_model)
    {
      vsf_one_process_chown_upload(p_sess, new_file_fd);
    }
    else
    {
      vsf_two_process_chown_upload(p_sess, new_file_fd);
    }
  }
  /* Are we required to lock this file? */
  if (tunable_lock_upload_files)
  {
    vsf_sysutil_lock_file_write(new_file_fd);
  }
  /* Must truncate the file AFTER locking it! */
  if (do_truncate)
  {
    vsf_sysutil_ftruncate(new_file_fd);
    vsf_sysutil_lseek_to(new_file_fd, 0);
  }
  if (!is_append && offset != 0)
  {
    /* XXX - warning, allows seek past end of file! Check for seek > size? */
    /* XXX - also, currently broken as the O_APPEND flag will always write
     * at the end of file. No known complaints yet; can easily fix if one
     * comes in.
     */
    vsf_sysutil_lseek_to(new_file_fd, offset);
  }
  if (is_unique)
  {
    struct mystr resp_str = INIT_MYSTR;
    str_alloc_text(&resp_str, "FILE: ");
    str_append_str(&resp_str, p_filename);
    remote_fd = get_remote_transfer_fd(p_sess, str_getbuf(&resp_str));
    str_free(&resp_str);
  }
  else
  {
    remote_fd = get_remote_transfer_fd(p_sess, "Ok to send data.");
  }
  if (vsf_sysutil_retval_is_error(remote_fd))
  {
    goto port_pasv_cleanup_out;
  }
  if (tunable_ascii_upload_enable && p_sess->is_ascii)
  {
    trans_ret = vsf_ftpdataio_transfer_file(p_sess, remote_fd,
                                            new_file_fd, 1, 1);
  }
  else
  {
    trans_ret = vsf_ftpdataio_transfer_file(p_sess, remote_fd,
                                            new_file_fd, 1, 0);
  }
  if (vsf_ftpdataio_dispose_transfer_fd(p_sess) != 1 && trans_ret.retval == 0)
  {
    trans_ret.retval = -2;
  }
  p_sess->transfer_size = trans_ret.transferred;
  if (trans_ret.retval == 0)
  {
    success = 1;
    vsf_log_do_log(p_sess, 1);
  }
  if (trans_ret.retval == -1)
  {
    vsf_cmdio_write(p_sess, FTP_BADSENDFILE, "Failure writing to local file.");
  }
  else if (trans_ret.retval == -2 || p_sess->abor_received)
  {
    vsf_cmdio_write(p_sess, FTP_BADSENDNET, "Failure reading network stream.");
  }
  else
  {
    vsf_cmdio_write(p_sess, FTP_TRANSFEROK, "File receive OK.");
  }
  check_abor(p_sess);
port_pasv_cleanup_out:
  port_cleanup(p_sess);
  pasv_cleanup(p_sess);
  if (tunable_delete_failed_uploads && created && !success)
  {
    str_unlink(p_filename);
  }
  vsf_sysutil_close(new_file_fd);
}

static void
handle_mkd(struct vsf_session* p_sess)
{
  int retval;
  resolve_tilde(&p_sess->ftp_arg_str, p_sess);
  vsf_log_start_entry(p_sess, kVSFLogEntryMkdir);
  str_copy(&p_sess->log_str, &p_sess->ftp_arg_str);
  prepend_path_to_filename(&p_sess->log_str);
  if (!vsf_access_check_file(&p_sess->ftp_arg_str))
  {
    vsf_cmdio_write(p_sess, FTP_NOPERM, "Permission denied.");
    return;
  }
  /* NOTE! Actual permissions will be governed by the tunable umask */
  retval = str_mkdir(&p_sess->ftp_arg_str, 0777);
  if (retval != 0)
  {
    vsf_cmdio_write(p_sess, FTP_FILEFAIL,
                    "Create directory operation failed.");
    return;
  }
  vsf_log_do_log(p_sess, 1);
  {
    static struct mystr s_mkd_res;
    static struct mystr s_tmp_str;
    str_copy(&s_tmp_str, &p_sess->ftp_arg_str);
    prepend_path_to_filename(&s_tmp_str);
    /* Double up double quotes */
    str_replace_text(&s_tmp_str, "\"", "\"\"");
    /* Build result string */
    str_alloc_text(&s_mkd_res, "\"");
    str_append_str(&s_mkd_res, &s_tmp_str);
    str_append_text(&s_mkd_res, "\" created");
    vsf_cmdio_write_str(p_sess, FTP_MKDIROK, &s_mkd_res);
  }
}

static void
handle_rmd(struct vsf_session* p_sess)
{
  int retval;
  resolve_tilde(&p_sess->ftp_arg_str, p_sess);
  vsf_log_start_entry(p_sess, kVSFLogEntryRmdir);
  str_copy(&p_sess->log_str, &p_sess->ftp_arg_str);
  prepend_path_to_filename(&p_sess->log_str);
  if (!vsf_access_check_file(&p_sess->ftp_arg_str))
  {
    vsf_cmdio_write(p_sess, FTP_NOPERM, "Permission denied.");
    return;
  }
  retval = str_rmdir(&p_sess->ftp_arg_str);
  if (retval != 0)
  {
    vsf_cmdio_write(p_sess, FTP_FILEFAIL,
                    "Remove directory operation failed.");
  }
  else
  {
    vsf_log_do_log(p_sess, 1);
    vsf_cmdio_write(p_sess, FTP_RMDIROK,
                    "Remove directory operation successful.");
  }
}

static void
handle_dele(struct vsf_session* p_sess)
{
  int retval;
  resolve_tilde(&p_sess->ftp_arg_str, p_sess);
  vsf_log_start_entry(p_sess, kVSFLogEntryDelete);
  str_copy(&p_sess->log_str, &p_sess->ftp_arg_str);
  prepend_path_to_filename(&p_sess->log_str);
  if (!vsf_access_check_file(&p_sess->ftp_arg_str))
  {
    vsf_cmdio_write(p_sess, FTP_NOPERM, "Permission denied.");
    return;
  }
  retval = str_unlink(&p_sess->ftp_arg_str);
  if (retval != 0)
  {
    vsf_cmdio_write(p_sess, FTP_FILEFAIL, "Delete operation failed.");
  }
  else
  {
    vsf_log_do_log(p_sess, 1);
    vsf_cmdio_write(p_sess, FTP_DELEOK, "Delete operation successful.");
  }
}

static void
handle_rest(struct vsf_session* p_sess)
{
  static struct mystr s_rest_str;
  filesize_t val = str_a_to_filesize_t(&p_sess->ftp_arg_str);
  if (val < 0)
  {
    val = 0;
  }
  p_sess->restart_pos = val;
  str_alloc_text(&s_rest_str, "Restart position accepted (");
  str_append_filesize_t(&s_rest_str, val);
  str_append_text(&s_rest_str, ").");
  vsf_cmdio_write_str(p_sess, FTP_RESTOK, &s_rest_str);
}

static void
handle_rnfr(struct vsf_session* p_sess)
{
  static struct vsf_sysutil_statbuf* p_statbuf;
  int retval;
  /* Clear old value */
  str_free(&p_sess->rnfr_filename_str);
  resolve_tilde(&p_sess->ftp_arg_str, p_sess);
  if (!vsf_access_check_file(&p_sess->ftp_arg_str))
  {
    vsf_log_start_entry(p_sess, kVSFLogEntryRename);
    str_copy(&p_sess->log_str, &p_sess->ftp_arg_str);
    prepend_path_to_filename(&p_sess->log_str);
    vsf_cmdio_write(p_sess, FTP_NOPERM, "Permission denied.");
    return;
  }
  /* Does it exist? */
  retval = str_stat(&p_sess->ftp_arg_str, &p_statbuf);
  if (retval == 0)
  {
    /* Yes */
    str_copy(&p_sess->rnfr_filename_str, &p_sess->ftp_arg_str);
    vsf_cmdio_write(p_sess, FTP_RNFROK, "Ready for RNTO.");
  }
  else
  {
    vsf_log_start_entry(p_sess, kVSFLogEntryRename);
    str_copy(&p_sess->log_str, &p_sess->ftp_arg_str);
    prepend_path_to_filename(&p_sess->log_str);
    vsf_cmdio_write(p_sess, FTP_FILEFAIL, "RNFR command failed.");
  }
}

static void
handle_rnto(struct vsf_session* p_sess)
{
  static struct mystr s_tmp_str;
  int retval;
  /* If we didn't get a RNFR, throw a wobbly */
  if (str_isempty(&p_sess->rnfr_filename_str))
  {
    vsf_cmdio_write(p_sess, FTP_NEEDRNFR,
                    "RNFR required first.");
    return;
  }
  resolve_tilde(&p_sess->ftp_arg_str, p_sess);
  vsf_log_start_entry(p_sess, kVSFLogEntryRename);
  str_copy(&p_sess->log_str, &p_sess->rnfr_filename_str);
  prepend_path_to_filename(&p_sess->log_str);
  str_append_char(&p_sess->log_str, ' ');
  str_copy(&s_tmp_str, &p_sess->ftp_arg_str);
  prepend_path_to_filename(&s_tmp_str);
  str_append_str(&p_sess->log_str, &s_tmp_str);
  if (!vsf_access_check_file(&p_sess->ftp_arg_str))
  {
    vsf_cmdio_write(p_sess, FTP_NOPERM, "Permission denied.");
    return;
  }
  /* NOTE - might overwrite destination file. Not a concern because the same
   * could be accomplished with DELE.
   */
  retval = str_rename(&p_sess->rnfr_filename_str, &p_sess->ftp_arg_str);
  /* Clear the RNFR filename; start the two stage process again! */
  str_free(&p_sess->rnfr_filename_str);
  if (retval == 0)
  {
    vsf_log_do_log(p_sess, 1);
    vsf_cmdio_write(p_sess, FTP_RENAMEOK, "Rename successful.");
  }
  else
  {
    vsf_cmdio_write(p_sess, FTP_FILEFAIL, "Rename failed.");
  }
}

static void
handle_nlst(struct vsf_session* p_sess)
{
  handle_dir_common(p_sess, 0, 0);
}

static void
prepend_path_to_filename(struct mystr* p_str)
{
  static struct mystr s_tmp_str;
  /* Only prepend current working directory if the incoming filename is
   * relative
   */
  str_empty(&s_tmp_str);
  if (str_isempty(p_str) || str_get_char_at(p_str, 0) != '/')
  {
    str_getcwd(&s_tmp_str);
    /* Careful to not emit // if we are in directory / (common with chroot) */
    if (str_isempty(&s_tmp_str) ||
        str_get_char_at(&s_tmp_str, str_getlen(&s_tmp_str) - 1) != '/')
    {
      str_append_char(&s_tmp_str, '/');
    }
  }
  str_append_str(&s_tmp_str, p_str);
  str_copy(p_str, &s_tmp_str);
}


static void
handle_sigurg(void* p_private)
{
  struct mystr async_cmd_str = INIT_MYSTR;
  struct mystr async_arg_str = INIT_MYSTR;
  struct mystr real_cmd_str = INIT_MYSTR;
  unsigned int len;
  struct vsf_session* p_sess = (struct vsf_session*) p_private;
  /* Did stupid client sent something OOB without a data connection? */
  if (p_sess->data_fd == -1)
  {
    return;
  }
  /* Get the async command - blocks (use data timeout alarm) */
  vsf_cmdio_get_cmd_and_arg(p_sess, &async_cmd_str, &async_arg_str, 0);
  /* Chop off first four characters; they are telnet characters. The client
   * should have sent the first two normally and the second two as urgent
   * data.
   */
  len = str_getlen(&async_cmd_str);
  if (len >= 4)
  {
    str_right(&async_cmd_str, &real_cmd_str, len - 4);
  }
  if (str_equal_text(&real_cmd_str, "ABOR"))
  {
    p_sess->abor_received = 1;
    /* This is failok because of a small race condition; the SIGURG might
     * be raised after the data socket is closed, but before data_fd is
     * set to -1.
     */
    vsf_sysutil_shutdown_failok(p_sess->data_fd);
  }
  else
  {
    /* Sorry! */
    vsf_cmdio_write(p_sess, FTP_BADCMD, "Unknown command.");
  }
  str_free(&async_cmd_str);
  str_free(&async_arg_str);
  str_free(&real_cmd_str);
}

static int
get_remote_transfer_fd(struct vsf_session* p_sess, const char* p_status_msg)
{
  int remote_fd;
  if (!pasv_active(p_sess) && !port_active(p_sess))
  {
    bug("neither PORT nor PASV active in get_remote_transfer_fd");
  }
  p_sess->abor_received = 0;
  if (pasv_active(p_sess))
  {
    remote_fd = vsf_ftpdataio_get_pasv_fd(p_sess);
  }
  else
  {
    remote_fd = vsf_ftpdataio_get_port_fd(p_sess);
  }
  if (vsf_sysutil_retval_is_error(remote_fd))
  {
    return remote_fd;
  }
  vsf_cmdio_write(p_sess, FTP_DATACONN, p_status_msg);
  if (vsf_ftpdataio_post_mark_connect(p_sess) != 1)
  {
    vsf_ftpdataio_dispose_transfer_fd(p_sess);
    return -1;
  }
  return remote_fd;
}

static void
check_abor(struct vsf_session* p_sess)
{
  /* If the client sent ABOR, respond to it here */
  if (p_sess->abor_received)
  {
    p_sess->abor_received = 0;
    vsf_cmdio_write(p_sess, FTP_ABOROK, "ABOR successful.");
  }
}