:: Re: [DNG] CLI backend: (E)SSID issu…
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Szerző: Rainer Weikusat
Dátum:  
Címzett: dng
Tárgy: Re: [DNG] CLI backend: (E)SSID issues
"tilt!" <tilt@???> writes:
> Hello,
>
> it has come to my attention that an SSID is defined by a
> (closed) IEEE standard as (I quote inofficial source [1]):
>
>> [...] "0-32 octets with arbitrary contents. A 0-length
>> SSID indicates the wildcard SSID (in probe request
>> frames for instance)"
>
> This means that
>
> #1 SSIDs can have length zero.
> #2 SSIDs can contain the zerobyte.


[...]

> b) I am currently unable to support case #2, because the
>    frontend does not pass the information "length of the
>    SSID" to the backend. Instead it passes ans an entry
>    of argv[] a C-type string which is a sequence of nonzero
>    bytes terminated by a zerobyte. Thus, the backend is not
>    capable of receiveing an SSID completely that contains
>    the zerobyte, and furthermore, the backend had no way of
>    determining the actual length of the SSID in bytes.


I wouldn't spend much time worrying about this: For the given scenario,
the ESSID is supposed to be intelligible by humans. Since 0 is not a
printable character, this makes it rather useless in the given context.

> Ceterum censeo standards should be open.


http://standards.ieee.org/about/get/

802.11 is among these. I used to work on a rather grotty Linux wireless
driver during some past project and thus needed some information re: how
this is supposed to work.