[Click] [RFC] Adding channel to wifi extra struct

[Roberto Riggio]

Hi,

actually the struct has the same size after the patch because
i've reduced the flag field from 32bit to 16bits. As far as I known
not all the 32 bits were used bu the flags (right?).

R.

Il 28/10/2010 17:37, Robert Sombrutzki ha scritto:
> Hi Roberto,
> it would be nice to have the channel in the struct click_wifi_extra, but
> please check include/click/packet_anno.hh.
> There are 24 bytes reserved for click_wifi_extra. Using your patch, the paint
> annos will be overwritten, because the size of struct click_wifi_extra will
> be 25 bytes. That's not a good idea.
> I think it's better to implement some channel annos without using struct
> click_wifi_extra, so that you can decide which annos you will overwrite.
> I did the following to implement an anns for the channel:
>
> #define CHANNEL_ANNO_OFFSET    46
> #define CHANNEL_ANNO_SIZE         1
> #define CHANNEL_ANNO(p)               ((p)->anno_u8(CHANNEL_ANNO_OFFSET))
> #define SET_CHANNEL_ANNO(p, v)   ((p)->set_anno_u8(CHANNEL_ANNO_OFFSET(v)))
>
> This will overwrite  PERFCTR_ANNO and IPSEC_SA_DATA_REFERENCE_ANNO. I don't
> use this annos. Just check include/click/packet_anno.hh and choose some
> annos, that are unused in your click elements/configuration.
>
> Robert
>
>
> On Donnerstag, 28. Oktober 2010, Roberto Riggio wrote:
>> Is the patch attached suitable for merging with click? If not, which
>> would be a more "clicky"
>> way of having a packet marked with the channel over which it was received?
>>
>> R.
>>
>> --
>> diff -urN click/elements/wifi/radiotapdecap.cc
>> click-wing/elements/wifi/radiotapdecap.cc
>> --- click/elements/wifi/radiotapdecap.cc    2010-10-15
>> 12:22:57.548443142 +0200
>> +++ click-wing/elements/wifi/radiotapdecap.cc    2010-10-15
>> 12:47:05.604443142 +0200
>> @@ -142,6 +142,9 @@
>>            if (rt_el_present(th, IEEE80211_RADIOTAP_DBM_ANTSIGNAL))
>>                ceh->rssi = *((u_int8_t *) rt_el_offset(th,
>> IEEE80211_RADIOTAP_DBM_ANTSIGNAL));
>>
>> +        if (rt_el_present(th, IEEE80211_RADIOTAP_CHANNEL))
>> +            ceh->channel = le16_to_cpu(*((u_int16_t *) rt_el_offset(th,
>> IEEE80211_RADIOTAP_CHANNEL)));
>> +
>>            if (rt_el_present(th, IEEE80211_RADIOTAP_DBM_ANTNOISE))
>>                ceh->silence = *((u_int8_t *) rt_el_offset(th,
>> IEEE80211_RADIOTAP_DBM_ANTNOISE));
>> diff -urN click/include/clicknet/wifi.h click-wing/include/clicknet/wifi.h
>> --- click/include/clicknet/wifi.h    2010-10-15 12:22:57.588443142 +0200
>> +++ click-wing/include/clicknet/wifi.h    2010-10-15 12:47:05.652443142
>> +0200
>> @@ -29,7 +29,9 @@
>>
>>    struct click_wifi_extra {
>>      uint32_t magic;
>> -  uint32_t flags;
>> +
>> +  uint16_t flags;
>> +  uint16_t channel;
>>
>>      uint8_t rssi;
>>      uint8_t silence;
>> _______________________________________________
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>