Re: Bug in telnet from inetutils-2.2: Insufficient buffer space for longish DISPLAY names

On Sat, Feb 05, 2022 at 05:18:01PM +0100, Erik Auerswald wrote:
[ots of interesting stuff deleted]

I agree with Erik's analysis and conclusions. As any "relevant" telnet implementation
should also implement the NEWENV option there should not even be a loss of functionality
by staying with the original buffer size.

> diff -Naur inetutils-2.2.orig/telnet/telnet.c inetutils-2.2.changed/telnet/telnet.c
> --- inetutils-2.2.orig/telnet/telnet.c	2021-05-25 17:54:19.000000000 +0200
> +++ inetutils-2.2.changed/telnet/telnet.c	2022-02-05 16:31:43.474464119 +0100
> @@ -1011,11 +1011,13 @@
>  	  /* Remote host, and display server must not be corrupted
>  	   * by truncation.  In addition, every character of telnet
>  	   * protocol must remain unsevered.  Check that DP fits in
> -	   * full within TEMP.  Otherwise report buffer error.
> +	   * full within TEMP.  Otherwise report buffer error and
> +	   * turn off the option.
>  	   */
>  	  if (strlen ((char *) dp) >= sizeof (temp) - 4 - 2)
>  	    {
> -	      printf ("lm_will: not enough room in buffer\n");
> +	      printf ("lm_will: not enough room in buffer for DISPLAY\n");
> +	      send_wont (TELOPT_XDISPLOC, 1);
>  	      break;
>  	    }
>  

I prefer Erik's patch over mine.

Kind regards
   Jörg

-- 
Joerg Mayer                                           <[email protected]>
We are stuck with technology when what we really want is just stuff that
works. Some say that should read Microsoft instead of technology.