ftpdataio.c

文件传输协议linux 下vsftpd2.1.0.tar.gz

  }
  if (loc_result.found && tunable_ls_recurse_enable)
  {
    p_subdir_list = &subdir_list;
  }
  vsf_ls_populate_dir_list(&dir_list, p_subdir_list, p_dir, p_base_dir_str,
                           p_option_str, p_filter_str, is_verbose);
  if (p_subdir_list)
  {
    int retval;
    str_copy(&dir_prefix_str, p_base_dir_str);
    str_append_text(&dir_prefix_str, ":\r\n");
    retval = ftp_write_str(p_sess, &dir_prefix_str, target);
    if (retval != 0)
    {
      failed = 1;
    }
  }
  if (!failed)
  {
    failed = write_dir_list(p_sess, &dir_list, target);
  }
  /* Recurse into the subdirectories if required... */
  if (!failed)
  {
    struct mystr sub_str = INIT_MYSTR;
    unsigned int num_subdirs = str_list_get_length(&subdir_list);
    unsigned int subdir_index;
    for (subdir_index = 0; subdir_index < num_subdirs; subdir_index++)
    {
      int retval;
      struct vsf_sysutil_dir* p_subdir;
      const struct mystr* p_subdir_str = 
        str_list_get_pstr(&subdir_list, subdir_index);
      if (str_equal_text(p_subdir_str, ".") ||
          str_equal_text(p_subdir_str, ".."))
      {
        continue;
      }
      str_copy(&sub_str, p_base_dir_str);
      str_append_char(&sub_str, '/');
      str_append_str(&sub_str, p_subdir_str);
      p_subdir = str_opendir(&sub_str);
      if (p_subdir == 0)
      {
        /* Unreadable, gone missing, etc. - no matter */
        continue;
      }
      str_alloc_text(&dir_prefix_str, "\r\n");
      retval = ftp_write_str(p_sess, &dir_prefix_str, target);
      if (retval != 0)
      {
        failed = 1;
        break;
      }
      retval = transfer_dir_internal(p_sess, is_control, p_subdir, &sub_str,
                                     p_option_str, p_filter_str, is_verbose);
      vsf_sysutil_closedir(p_subdir);
      if (retval != 0)
      {
        failed = 1;
        break;
      }
    }
    str_free(&sub_str);
  }
  str_list_free(&dir_list);
  str_list_free(&subdir_list);
  str_free(&dir_prefix_str);
  if (!failed)
  {
    return 0;
  }
  else
  {
    return -1;
  }
}

/* XXX - really, this should be refactored into a "buffered writer" object */
static int
write_dir_list(struct vsf_session* p_sess, struct mystr_list* p_dir_list,
               enum EVSFRWTarget target)
{
  /* This function writes out a list of strings to the client, over the
   * data socket. We now coalesce the strings into fewer write() syscalls,
   * which saved 33% CPU time writing a large directory.
   */
  int retval = 0;
  unsigned int dir_index_max = str_list_get_length(p_dir_list);
  unsigned int dir_index;
  struct mystr buf_str = INIT_MYSTR;
  str_reserve(&buf_str, VSFTP_DIR_BUFSIZE);
  for (dir_index = 0; dir_index < dir_index_max; dir_index++)
  {
    str_append_str(&buf_str, str_list_get_pstr(p_dir_list, dir_index));
    if (dir_index == dir_index_max - 1 ||
        str_getlen(&buf_str) +
          str_getlen(str_list_get_pstr(p_dir_list, dir_index + 1)) >
            VSFTP_DIR_BUFSIZE)
    {
      /* Writeout needed - we're either at the end, or we filled the buffer */
      int writeret = ftp_write_str(p_sess, &buf_str, target);
      if (writeret != 0)
      {
        retval = 1;
        break;
      }
      str_empty(&buf_str);
    }
  }
  str_free(&buf_str);
  return retval;
}

struct vsf_transfer_ret
vsf_ftpdataio_transfer_file(struct vsf_session* p_sess, int remote_fd,
                            int file_fd, int is_recv, int is_ascii)
{
  if (!is_recv)
  {
    if (is_ascii || p_sess->data_use_ssl)
    {
      return do_file_send_rwloop(p_sess, file_fd, is_ascii);
    }
    else
    {
      filesize_t curr_offset = vsf_sysutil_get_file_offset(file_fd);
      filesize_t num_send = calc_num_send(file_fd, curr_offset);
      return do_file_send_sendfile(
        p_sess, remote_fd, file_fd, curr_offset, num_send);
    }
  }
  else
  {
    return do_file_recv(p_sess, file_fd, is_ascii);
  }
}

static struct vsf_transfer_ret
do_file_send_rwloop(struct vsf_session* p_sess, int file_fd, int is_ascii)
{
  static char* p_readbuf;
  static char* p_asciibuf;
  struct vsf_transfer_ret ret_struct = { 0, 0 };
  unsigned int chunk_size = get_chunk_size();
  char* p_writefrom_buf;
  int prev_cr = 0;
  if (p_readbuf == 0)
  {
    vsf_secbuf_alloc(&p_readbuf, VSFTP_DATA_BUFSIZE);
  }
  if (is_ascii)
  {
    if (p_asciibuf == 0)
    {
      /* NOTE!! * 2 factor because we can double the data by doing our ASCII
       * linefeed mangling
       */
      vsf_secbuf_alloc(&p_asciibuf, VSFTP_DATA_BUFSIZE * 2);
    }
    p_writefrom_buf = p_asciibuf;
  }
  else
  {
    p_writefrom_buf = p_readbuf;
  }
  while (1)
  {
    unsigned int num_to_write;
    int retval = vsf_sysutil_read(file_fd, p_readbuf, chunk_size);
    if (vsf_sysutil_retval_is_error(retval))
    {
      ret_struct.retval = -1;
      return ret_struct;
    }
    else if (retval == 0)
    {
      /* Success - cool */
      return ret_struct;
    }
    if (is_ascii)
    {
      struct bin_to_ascii_ret ret =
          vsf_ascii_bin_to_ascii(p_readbuf,
                                 p_asciibuf,
                                 (unsigned int) retval,
                                 prev_cr);
      num_to_write = ret.stored;
      prev_cr = ret.last_was_cr;
    }
    else
    {
      num_to_write = (unsigned int) retval;
    }
    retval = ftp_write_data(p_sess, p_writefrom_buf, num_to_write);
    if (!vsf_sysutil_retval_is_error(retval))
    {
      ret_struct.transferred += (unsigned int) retval;
    }
    if (vsf_sysutil_retval_is_error(retval) ||
        (unsigned int) retval != num_to_write)
    {
      ret_struct.retval = -2;
      return ret_struct;
    }
  }
}

static struct vsf_transfer_ret
do_file_send_sendfile(struct vsf_session* p_sess, int net_fd, int file_fd,
                      filesize_t curr_file_offset, filesize_t bytes_to_send)
{
  int retval;
  unsigned int chunk_size = 0;
  struct vsf_transfer_ret ret_struct = { 0, 0 };
  filesize_t init_file_offset = curr_file_offset;
  filesize_t bytes_sent;
  if (p_sess->bw_rate_max)
  {
    chunk_size = get_chunk_size();
  }
  /* Just because I can ;-) */
  retval = vsf_sysutil_sendfile(net_fd, file_fd, &curr_file_offset,
                                bytes_to_send, chunk_size);
  bytes_sent = curr_file_offset - init_file_offset;
  ret_struct.transferred = bytes_sent;
  if (vsf_sysutil_retval_is_error(retval))
  {
    ret_struct.retval = -2;
    return ret_struct;
  }
  else if (bytes_sent != bytes_to_send)
  {
    ret_struct.retval = -2;
    return ret_struct;
  }
  return ret_struct; 
}

static filesize_t
calc_num_send(int file_fd, filesize_t init_offset)
{
  static struct vsf_sysutil_statbuf* s_p_statbuf;
  filesize_t bytes_to_send;
  /* Work out how many bytes to send based on file size minus current offset */
  vsf_sysutil_fstat(file_fd, &s_p_statbuf);
  bytes_to_send = vsf_sysutil_statbuf_get_size(s_p_statbuf);
  if (init_offset < 0 || bytes_to_send < 0)
  {
    die("calc_num_send: negative file offset or send count");
  }
  /* Don't underflow if some bonehead sets a REST greater than the file size */
  if (init_offset > bytes_to_send)
  {
    bytes_to_send = 0;
  }
  else
  {
    bytes_to_send -= init_offset;
  }
  return bytes_to_send;
}

static struct vsf_transfer_ret
do_file_recv(struct vsf_session* p_sess, int file_fd, int is_ascii)
{
  static char* p_recvbuf;
  unsigned int num_to_write;
  struct vsf_transfer_ret ret_struct = { 0, 0 };
  unsigned int chunk_size = get_chunk_size();
  int prev_cr = 0;
  if (p_recvbuf == 0)
  {
    /* Now that we do ASCII conversion properly, the plus one is to cater for
     * the fact we may need to stick a '\r' at the front of the buffer if the
     * last buffer fragment eneded in a '\r' and the current buffer fragment
     * does not start with a '\n'.
     */
    vsf_secbuf_alloc(&p_recvbuf, VSFTP_DATA_BUFSIZE + 1);
  }
  while (1)
  {
    const char* p_writebuf = p_recvbuf + 1;
    int retval = ftp_read_data(p_sess, p_recvbuf + 1, chunk_size);
    if (vsf_sysutil_retval_is_error(retval))
    {
      ret_struct.retval = -2;
      return ret_struct;
    }
    else if (retval == 0 && !prev_cr)
    {
      /* Transfer done, nifty */
      return ret_struct;
    }
    num_to_write = (unsigned int) retval;
    ret_struct.transferred += num_to_write;
    if (is_ascii)
    {
      /* Handle ASCII conversion if we have to. Note that using the same
       * buffer for source and destination is safe, because the ASCII ->
       * binary transform only ever results in a smaller file.
       */
      struct ascii_to_bin_ret ret =
        vsf_ascii_ascii_to_bin(p_recvbuf, num_to_write, prev_cr);
      num_to_write = ret.stored;
      prev_cr = ret.last_was_cr;
      p_writebuf = ret.p_buf;
    }
    retval = vsf_sysutil_write_loop(file_fd, p_writebuf, num_to_write);
    if (vsf_sysutil_retval_is_error(retval) ||
        (unsigned int) retval != num_to_write)
    {
      ret_struct.retval = -1;
      return ret_struct;
    }
  }
}

static unsigned int
get_chunk_size()
{
  unsigned int ret = VSFTP_DATA_BUFSIZE;
  if (tunable_trans_chunk_size < VSFTP_DATA_BUFSIZE &&
      tunable_trans_chunk_size > 0)
  {
    ret = tunable_trans_chunk_size;
    if (ret < 4096)
    {
      ret = 4096;
    }
  }
  return ret;
}