net: tftp: fix progress marker for file transfer

During packet sequence number wraparound the show_block_marker() API was
not called, as a result the progress marker doesn't stay within column
boundary. Use position in file instead of sequence number to align the
marker.

Signed-off-by: Ravik Hasija <rahasij at linux.microsoft.com>
---
 net/tftp.c | 16 +++++++++-------
 1 file changed, 9 insertions(+), 7 deletions(-)

On Fri, May 8, 2020 at 2:16 PM Ravik Hasija <rahasij at linux.microsoft.com> wrote:
>
> During packet sequence number wraparound the show_block_marker() API was
> not called, as a result the progress marker doesn't stay within column
> boundary. Use position in file instead of sequence number to align the
> marker.
>
> Signed-off-by: Ravik Hasija <rahasij at linux.microsoft.com>
> ---
>  net/tftp.c | 16 +++++++++-------
>  1 file changed, 9 insertions(+), 7 deletions(-)
>
> diff --git a/net/tftp.c b/net/tftp.c
> index 34488b76c8..8039694ef2 100644
> --- a/net/tftp.c
> +++ b/net/tftp.c
> @@ -229,9 +229,11 @@ static void tftp_timeout_handler(void);
>
>  static void show_block_marker(void)
>  {
> +       ulong pos;
> +
>  #ifdef CONFIG_TFTP_TSIZE
>         if (tftp_tsize) {
> -               ulong pos = tftp_cur_block * tftp_block_size +
> +               pos = tftp_cur_block * tftp_block_size +
>                         tftp_block_wrap_offset;
>                 if (pos > tftp_tsize)
>                         pos = tftp_tsize;
> @@ -243,9 +245,11 @@ static void show_block_marker(void)
>         } else
>  #endif
>         {
> -               if (((tftp_cur_block - 1) % 10) == 0)
> +               pos = (tftp_cur_block - 1) +
> +                       (tftp_block_wrap * TFTP_SEQUENCE_SIZE);
> +               if ((pos % 10) == 0)
>                         putc('#');
> -               else if ((tftp_cur_block % (10 * HASHES_PER_LINE)) == 0)
> +               else if (((pos + 1) % (10 * HASHES_PER_LINE)) == 0)
>                         puts("\n\t ");
>         }
>  }
> @@ -278,9 +282,8 @@ static void update_block_number(void)
>                 tftp_block_wrap++;
>                 tftp_block_wrap_offset += tftp_block_size * TFTP_SEQUENCE_SIZE;
>                 timeout_count = 0; /* we've done well, reset the timeout */
> -       } else {
> -               show_block_marker();
>         }
> +       show_block_marker();
>  }
>
>  /* The TFTP get or put is complete */
> @@ -514,8 +517,6 @@ static void tftp_handler(uchar *pkt, unsigned dest, struct in_addr sip,
>                 len -= 2;
>                 tftp_cur_block = ntohs(*(__be16 *)pkt);
>
> -               update_block_number();
> -
>                 if (tftp_state == STATE_SEND_RRQ)
>                         debug("Server did not acknowledge timeout option!\n");
>
> @@ -541,6 +542,7 @@ static void tftp_handler(uchar *pkt, unsigned dest, struct in_addr sip,
>                         break;
>                 }
>
> +               update_block_number();
>                 tftp_prev_block = tftp_cur_block;
>                 timeout_count_max = tftp_timeout_count_max;
>                 net_set_timeout_handler(timeout_ms, tftp_timeout_handler);
> --
> 2.17.1
>
Reviewed-By: Ramon Fried <rfried.dev at gmail.com>