Hi Robert, Are u sure on this?
Packets for monitor device comes from ieee80211_output.c -> ieee80211_monitor_encap() on this function the channel value is not processed into ieee80211_phy_params ph, for example: rate is processed: case IEEE80211_RADIOTAP_RATE: ph->rate0 = *p; p++; break; channel is not processed: case IEEE80211_RADIOTAP_CHANNEL: /* 2 x 16-bit */ p = start + roundup(p - start, 2) + 4; break; Regards Javier On Mon, Jul 27, 2009 at 5:49 PM, Robert Sombrutzki<[email protected]> wrote: > Hi, > i think, it's not the best way to use a sysctl to set the channel, because you > can not control which packets are sent on which channel, since you have > several queues. Example: you have packet a and b , you want to sent packet a > on channel 1 and b on 2. How do you want to control that the new channel is > set between these two packets ? Of course, you can delay packet b until the > new channel is set, but that has no good performance. I think it better to > set the channel using an annotation on the packet. You can extend the > ath-header (use AthdescEncap) with an extra field for the channel, which > should used for the packet. In the madwifi-driver (e.g. in > ieee80211_output.c), you check for the encap-type, the field in the header > and the channel and switch to the new channel ( struct ieee80211com includes > pointer to the channel-switch-function: ic_set_channel). The problem here is, > that you have to sent a packet to switch the channel, but therefor it is > precise. To switch the channel without transmitting a packet, you can > generate a packet which just initiates the changing the channel, but which is > discard by the driver afterwards. According to the channel you can mark such > kind of packets using an extention to the ath-header. > I use this solution and it works well. > > Regards, > Robert >>Hi, >> >>Can someone please advise me how to write something in /proc/sys in a click >>event? I need to change the channel in MadWifi upon reception of a control >>packet. I am planning on writing a sysctl handler in madwifi to change the >>channel upon request, and I need to trigger it using Click. If someone has a >>better suggestion to do this - I'll be glad to know! >> >>Thanks for your help and time. >> >>Ashish > _______________________________________________ > click mailing list > [email protected] > https://amsterdam.lcs.mit.edu/mailman/listinfo/click > _______________________________________________ click mailing list [email protected] https://amsterdam.lcs.mit.edu/mailman/listinfo/click
