madwifi s podporou 802.11h

8.6.2007 00:10 | Přečteno: 1225× | Linux

Poslední dobou nemám moc času (spousta práce), takže sem ani moc nepíšu, dnes bych chtěl jen v rychlosti oznámit super novinku, která mi dnes tak troch vyrazila dech :)

Dnes jsem kontroloval stránky http://madwifi­.org kde jsem narazil na patch přidávající podporu pro normu 802.11h na všech atherosech používajících madwifi ovladače.

Patch je samozřejmě ještě ve vývoji, ale všechny důležité funkce by měly chodit.
Z diskuze pod patchem:
This patch is a work in progress for regulatory testing and compliance.

Included:

• Updated channel and power IE values (from previous patch contributed by Mike Wrobel)
• Uniform channel spreading algorithms (from previous patch contributed by Mike Wrobel)
• Client association restrictions / channel changing algorithms for DFS (how many common channels needed to associate, tradeoffs in dropped clients for RSSI gained, etc.)
• Radar pulse detection
• DFS / channel availability check
• DFS / co-channel interference avoidance (Radar detection / reaction)
• change channels
• stay off channel for channel non-occupancy limit
• restore channel to service after timeout
• return to channel if it was the 'preferred channel
• Continuous transmission mode (for testing)
• Radar event injection (for testing)
• DFS radar detection testing (detection without channel switching) (for testing)
• DFS radar detection timing tweaks (for testing)

Still remaining:

• ALL pulses are all treated as radar right now. The algorithm must be implemented that checks events over time to detect periodicity of pulses and bursts (to filter out non-priority signals) from consideration.
• After the first pulses, and during analysis just mentioned, reduce duty cycle to increase chances of detection.
• The channel chosen when radar is detected probably isn't using uniform channel spreading.

Won't do:

• Station DFS can notify the AP of a radar detection with an unsolicited IE indicating the interference.
• I am not adding this for security reasons as a DoS is possible without proper consideration.

Ještě jsem to netestoval, ale brzy určitě budu, vypadá to ještě lépe, než na mikrotiku, kde je podpora 802.11h podivná.

       

Komentáře

[hwsoft]

cau, jsem na tom s casem podobne, madwifi-devel sice sleduju, ale uz neni cas na vetsi pokusy. Pokud se do toho das, rad se dozvim neco noveho, pripadne muzu fungovat jako pokusny kralik, mame dva testovaci spoje, kde nic dulezityho netece.

[Zdeněk Štěpánek]

To ja se taky tesim, sice zatim nemam kde testovat jako hwsoft, ale na test by to slo, vsak oni ten vypadek prezijou.

Doufam ze to chlapci dotahnou do poradnyho konce, protoze jestopi to pak dopadne jak ma tak to nasadim, nastavim vzdalenost, urcim pasmo kanalu od-do a ono to pojede. Aniz by nekdo rusil me, aniz bych nekoho rusil ja, doufam ze to neni jen pohadka.

Zdenek