[lwip-devel] [patch #9876] Const-correctness fixes, pointer types for buffers & couple minor tweaks

[Freddie Chopin]

URL:
  <https://savannah.nongnu.org/patch/?9876>

                 Summary: Const-correctness fixes, pointer types for buffers &
couple minor tweaks
                 Project: lwIP - A Lightweight TCP/IP stack
            Submitted by: freddie_chopin
            Submitted on: Thu 05 Dec 2019 09:25:38 PM UTC
                Category: PPP
                Priority: 5 - Normal
                  Status: None
                 Privacy: Public
             Assigned to: None
        Originator Email: 
             Open/Closed: Open
         Discussion Lock: Any
         Planned Release: None

    _______________________________________________________

Details:

The major part of these patches is changing `u8_t*` to `const void*` for
pppos_input_tcpip(), pppos_input() and pppos_output_cb_fn(). There is no good
reason to use non-const buffers for these functions (and this is possibly
dangerous - why should output callback modify what lwIP gives it or why should
lwIP modify in-place what was given by user?).

While changes to pppos_input_tcpip() and pppos_input() are mostly harmless and
should not affect any application, change to pppos_output_cb_fn() (which I
actually consider the most important) is going to be non-backward compatible
and breaking change in all possible cases. Unfortunately users will now have
to change their prototypes (and maybe also slightly change the
implementation). This is evident from the changes which I had to make in the
example apps.

There is a similar problem for the functions from sio.h - while it may be
debatable whether one should use `u8_t*` or `void*`, functions which do
"writes" should use const pointers in all cases. Please let me know whether
you're open to changing that.

Please compile-test before (hopefully) submitting, as I was probably not able
to build every important combination of options and neither did I try to build
the test apps.



    _______________________________________________________

File Attachments:


-------------------------------------------------------
Date: Thu 05 Dec 2019 09:25:38 PM UTC  Name:
0001-Use-const-void-instead-of-u8_t-in-pppos_input_tcpip.patch  Size: 2KiB  
By: freddie_chopin

<http://savannah.nongnu.org/patch/download.php?file_id=48006>
-------------------------------------------------------
Date: Thu 05 Dec 2019 09:25:38 PM UTC  Name:
0002-Use-const-void-instead-of-u8_t-in-pppos_input.patch  Size: 2KiB   By:
freddie_chopin

<http://savannah.nongnu.org/patch/download.php?file_id=48007>
-------------------------------------------------------
Date: Thu 05 Dec 2019 09:25:38 PM UTC  Name:
0003-Remove-useless-cast-from-pppos_input_sys.patch  Size: 846B   By:
freddie_chopin

<http://savannah.nongnu.org/patch/download.php?file_id=48008>
-------------------------------------------------------
Date: Thu 05 Dec 2019 09:25:38 PM UTC  Name:
0004-Use-const-void-instead-of-u8_t-in-pppos_output_cb_fn.patch  Size: 3KiB  
By: freddie_chopin

<http://savannah.nongnu.org/patch/download.php?file_id=48009>

    _______________________________________________________

Reply to this item at:

  <https://savannah.nongnu.org/patch/?9876>

_______________________________________________
  Message sent via Savannah
  https://savannah.nongnu.org/