Hello ppl ;-) Molis xthes teleiwse to Ottawa Linux Symposium 2008 sta plaisia tou opoiou eixame to 3o wireless summit. To wireless summit einai xontrika ena meeting/workshop olwn twn developers pou asxolountai h endiaferontai na asxolhthoun me wireless drivers h genikotera wireless applications. So merika ap' ta themata pou mas apasxolhsan kai pou vriskomaste (ena mini report ap' to prohgoumeno wireless summit tha vreite edw -> http://www.awmn.net/forum/viewtopic.php?f=42&t=27930): ---Status report--- QoS: Katarxas pleon exoume synolika ston pyrhna mutiqueue support, pou shmainei xontrika oti kathe network driver sto transmit path tou xrhsimopoiei polles oures ki etsi mporoume na ylopoihsoume politikes QoS poly kalytera. H idea ksekinhse arxika ap' to wme pou yparxei stis asyrmates kartes (to 802.11e orizei oti exoume metavlhta inter-frame space kai metavlhto contention window, pou epitrepei an thelete to kalytero dynato "strimogma" twn frames sto kanali) kai proxorise kai stous ethernet klp drivers (perissotera edw -> http://lwn.net/Articles/288940/). Eixame loipon mia syzhtish sxetika me to pws xrhsimopoioume to neo framework toso sto mac80211 stack oso kai stous drivers kathos kai mia genikh syzhthsh gia hw queues kai aggregation (vl 802.11n parakatw). 802.11n: Enw h vasikh ylopoihsh yparxei sto mac80211, eixame mia syzhthsh gia to pws tha "katharisoume" ton kwdika (kyriws me ta paidia ap' thn Intel pou exoun grapsei to megalytero kommati tou) kai pws mporoume na glytwsoume kapoio overhead klp. Syntoma tha exoume ekselikseis sto sygekrimeno thema afou h syzhthsh htan poly endiaferousa kai vghkan nees idees (h alhtheia einai oti me to rev. engineering exw xasei arketes apo tis ekselikseis sto mac80211 opote an thelete na rwtisete kati poio sygekrimeno gia to 802.11n dokimaste thn linux-wireless). Spectrum Management (DFS/Regulatory control): Ena ap' ta megalytera themata pou antimetopizoume einai ayto tou regulatory control, koinws pws vriskoume th xrysh tomh metaksy enos open-source leitourgikou kai twn kanonwn twn FCC/ETSI. To thema tou regulatory control empodizei toso emas na ypostiriksoume plhrws kapoies leitourgies swsta, oso kai tous vendors na dwsoun open source drivers (mias kai fovountai oti h FCC tha tous kinigisei). Eixame poly entones ekselikseis prosfata loipon afou h Atheros edwse open-source ton neo ths driver ath9k, pou ypostirizei ta kainouria 802.11n chipsets (oxi mono ta ar9xxx alla kai to AR5416/AR5418) ths kai pou exei vrei to dromo tou gia ton kernel (mallon ap' thn ekdosh 2.6.28), prokalontas tous ypoloipous vendors (kai kyriws thn broadcom pou efage xontro giouxarisma) na kanoun to idio. H thesh loipon ths Atheros (meta apo POLYYY syzhthsh telika phstikan) einai oti telika kaneis den mporei na ftiaksei mia lysh pou tha einai 100% asfalhs, oti to "security through obscurity" den poianei kai oti akoma kai etairies pou xrhsimopoioun firmware, exoun hackeftei (mpixth gia thn broadcom opou ta paidia pou kanoun rev. engineer kontevoun na grapsoun open-source firmware :P). Etsi anti na kanoun thn papia prospathoun na apotrepsoun to abuse twn kartwn tous apo tous reverse engineered drivers kai gi' ayto synergazontai energa me thn koinothta pros ayth th kateythynsh (siga siga tha doulepsoume mazi kai ston ath5k). Exei mpei se troxia o Central Regulatory Domain Agent, ousiastika prokeitai gia ena framework pou tha yiothetisoun oi drivers kai vasei tou opoiou tha rythmizoun (h kalytera tha kanoun limit) to transmition power kai to evros twn syxnothtwn pou ypostirizoun se kathe xwra. Perissoteres plhrofories edw -> http://wireless.kernel.org/en/developers/Regulatory. Kapoia updates sto keimeno einai oti den tha xrhsimopoioume kapoion extra daemon alla to udev, px. opws fortwnetai to firmware otan kanoume up ena interface, tha fortwnetai kai h database pou antistoixei sth xwra pou vrisketai xrhsimopoiwntas plhrofories toso ap' to 802.11d oso kai apo thn idia thn karta, px EEPROM. Gia tis kartes pou den exoume tetoies plhrofories (dld oses exoun ginei rev. engineering kai den parexoun plhrofories gia to regulatory domain px. -pali mphxth sthn broadcom :P-) tha prospathoume na pairnoume kapoia plhroforia ap' to userspace (px. na orizei o xrhsths th xwra pou vrisketai -analamvanontas thn eythinh panta-). Telos yphrkse mia idea gia enan Frequency Broker pou ousiastika tha einai ena framework h daemon pou tha epilegei kanali/mpanda xrhsimopoiwntas plhrofories apo olles tis asyrmates syskeves pou diathetei to pc, px. an exete energopoihmeno bluetooth, tha kserei apo prin se poia syxnothta paizei, opote den tha thn xrhsimopoiei px. gia wi-fi an pate na sthsete ap. 802.11s (wireless mesh): An kai to 802.11s einai akoma draft, ta paidia pou doulepsan sthn ylopoihsh tou sto OLPC (sto firmware twn Marvell -h opoia fainetai na to gyrizei ksafnika kai ayth se open-source !), ylopoihsan to kainourio draft (oxi plhrws alla kanei ta vasika) sto mac80211. Syzhtisame loipon pou vriskomaste, ti leipei ap' to implementation (kai ap' to draft) kai epishs mathame oti to implementation sto mac80211 den einai symvato me to implementation tou OLPC to opoio vasizetai se paliotero draft (ara den mporeite na sthsete mesh diktyo metaksy OLPC kai kapoiou mac80211 driver). To 802.11s exei apoktisei poly endiaferon kai arketoi doulevoun se ayto (erevnhtika idrymata klp) kai anamenoume ekselikseis, pantws mexri twra to Linux einai to mono leitourgiko pou ylopoiei ayto to protypo kai to kataxarhkame :P RF Kill/Power management: To RF Kill einai ena framework gia na xrhsimopoioume ta diafora switches (hw/acpi/sw -px fn + kati) twn laptops gia na anoigokleinoun tis asyrmates kartes (bluetooth/wi-fi klp). To kyriws provlhma htan me to firmware loading stis kartes pou to xreiazontai kai ti akrivws kanoume se mia periptwsh pou to switch energopoieitai h apenergopoieitai. Alloi elegan oti to RF Kill prepei na kanei apla disable to PHY kai oxi synolika thn karta gia na mporoun oi kartes pou xrhsimopoioun firmware na epanerxontai poio grhgora klp, alloi -symperilamvanomenou ki emou- pistevane oti to RF Kill prepei na einai to idio me to ifconfig down (na rixnei dhladh teleiws thn karta) klp. Katalhksame loipon sto oti prepei otan to switch einai kleisto na vazoume thn karta sto ypsilotero dynato power save mode kata to opoio mporei na epanelthei xwris na ksanafortwsoume ton driver, an h karta katanalwnei energeia otan exei loaded firmware, tote thn rixnoume, an oxi apla thn kanoume reset kai thn afhnoume na kathetai -yparxoun kartes pou den katanalwnoun energeia otan einai apla up, akoma kai kartes pou xrhsimopoioun firmware, opote se aytes den kanoume ifconfig down px-. Ayto akougetai aploiko alla den einai, prokyptei ena provlhma me kapoies kartes pou xreiazontai firmware px. gia na mas kanoun report thn MAC address tous (kai ara tha exoume provlhma px. me to udev kai to renaming twn kartwn) kai prokyptoun kai alla themata (px. wake on wlan klp). Gia to thema ths MAC fainetai na katalhksame (vl. prosfato patch sthn linux-wireless) sto oti otan h karta den mas kanei report th MAC otan einai down/rf-killed, tha ths vazoume manually thn 01:00:00... (h 00:00... einai registered :P). Opote ama deite kamia periergh mac kai kana periergo onoma sto wi-fi interface sas (giati kata pasa pithanothta tha enhmerwsoume kai to udev gi' ayto), mhn psaxneste. Driver Status: Kaname o kathenas mia parousiash sxetika me to pou vrisketai o kathe driver kai genikws ta pragmata pane poly kala, eimaste ap' tis poio energes omades ston kernel (4h se commits) ! Tha exete poly kalyterh eikona an deite th lista linux-wireless (to wiki einai ligo outdated) gia to pou vrisketai o kathe driver. Oson afora ton ath5k, prosfata esteila ena patch series pou ypostirizei tis pci-e kartes symperilamvanomenhs ths RF2425 (ayth pou exei to eeepc), opote kleisame me to support twn legacy kartwn (a/b/g) kai menoun oi 11n (pou ypostirizontai ap' ton ath9k -vl parapanw- me ton opoio kapoia stigmh tha kanoume merge) kathws kai ta diafora themata performance. Mporeite na vreite ena snapshot edw -> http://www.kernel.org/pub/linux/kernel/people/mickflemm/compat-wireless-2008-07-03-ath5k.tar.bz2, enw ta patches gia to wireless-testing tree tha ta vreite edw -> http://www.kernel.org/pub/linux/kernel/people/mickflemm/patch-series-8.tar.bz2. Exoun hdh ginei submited kai syntoma tha ginoun commit. Eixame epishs kapoies anafores ap' thn intel sxetika me tous iwlwifi opou diorthwnoun diafora bugs kai strwnoun ton kwdika (idiaitera oson afora to 11n kommati), enw exoun vgei kata kairous kai diafora endiaferonta patches metaksy twn opoiwn ki ena pou ypostirizei packet injection. Oson afora ton b43, to rev. engineering exei sxedon teleiwsei, ta specs grafontai klp kai menei na graftei o kwdikas (clean room), ta paidia exoun sxedon grapsei diko tous firmware to opoio omws sth parousa fash kanei hang meta to prwto paketo pou kanei transmit (kanei rx kanonika). H Broadcom arneitai na dwsei specs h kwdika (steilan omws ton Henry o opoios einai poly kalo atomo kai prospathei ki o idios na tous pisei -to ti akouse o kakomoirhs de legetai :P- kai fainetai na skeftontai toulaxiston to licensing tou firmware) alla ta paidia tou b43 einai apofasismenoi na tous apoteleiwsoun :P. Eixame epishs enan apo th Ralink o opoios den evgale axna :P. ---Current work--- AP (master mode) support: O kwdikas gia thn ypostiriksh master mode yparxei hdh sto mac80211 stack alla akoma kapoia scenarios den exoun ylopoihthei kai ws ek toutou den einai akoma standards-compliant. Epishs exoume akoma poly douleia oson afora to DFS (aparaithto an theloume na sthsoume ena AP sta 5Ghz -einai kommati tou protypou 802.11a), to APSD (automatic power save delivery) kai to U-APSD (urgent automatic power save delivery). Syntoma elpizoume ayth h leitourgia (pou th zhtaei polys kosmos) na einai diathesimh gia tous xrhstes (pros to paron xreiazeste ena patch gia na peiramatisteite -rixte mia matia sthn lista linux-wireless). cfg80211/nl80211: Syzhtisame gia to pote tha ksefortwthoume ta wireless extentions kai pote tha proxwrisoume pros to userspace MLME. Den katalhksame kapou alla genikws eipame oti exoume ftasei se ena shmeio opou ta wireless extensions mas kratane pisw sto development, enw xreiazomaste perissoterous developers na asxolithoun me to sygekrimeno API afou o Johannes exei minei monos tou. CRDA: vl. parapanw (spectrum management) Encrypted management frames (802.11w): O kwdikas einai sxedon etoimos kai apla epivevaiwsame oti to implementation proxwraei kanonika kai otan erthei to userspace MLME tha eimaste etoimoi. Hw simulator: Exoume pleon ap' ton Jouni enan simulator gia na mporoume na testaroume to protocol stack. Ousiastika prokeitai gia ena virtual hw interface me ton driver tou, panw sto opoio mporoume na treksoume diafora tests, injection klp. Den exoume etoima test scripts akoma alla exei parei to dromo tou... WiMAX: H Intel mas ekane parousiash tou framework pou exei ftiaksei gia to support twn wimax kartwn ths sto linux (vl. http://www.linuxwimax.org/) kai mas eksighse perippou ti paizei me tous providers kai ti apaithseis exoun klp. En oligois oi perissoteroi service providers exoun ws apaithsh oi kartes na einai fullmac (h syzhthsh ksekinhse gia to an mporoume na exoume master mode sto wimax), enw prepei na ylopoihsoume diafora pragmata sto userspace (deite to site kai tha katalavete). H Intel mas edwse merikes kartes (engineering samples) wimax + 11n gia na paiksoume kai na ths steiloume feedback. ---Future work--- lib80211/full mac drivers: Oi kartes full mac, ylopoioun olo to 802.11 stack sto firmware kai ara gia ton pyrhna einai apla ethernet devices. Akoma omws kai oi fullmac drivers exoun arketa koina xarakthristika kai vlepoume syxna code duplication. Gia kairo syzhtagame gia ena allo framework pou to eipame lib80211, gia tous fullmac drivers, etsi wste na glytwsoume apo ayto to fainomeno (px. http://article.gmane.org/gmane.linux.kernel.wireless.general/8746). Telika fainetai oti to cfg80211 einai poio endiaferon kai mallon o koinos kwdikas tha paei ekei. Ousiastika to mono pou xreiazomaste ston driver einai na ylopoiei to cg80211 API (gia na mporei na rythmizetai h karta -essid klp-), etsi gia tous fullmac drivers mallon tha ftiaxtei kapoio estention sto cfg80211, akoma den to exoume ksekatharisei. Rate control algorithms: Mexri stigmhs exoume enan default algorithmo gia rate control, ton PID controler (http://en.wikipedia.org/wiki/PID_controller), gia olous tous drivers, ti ginetai omws an kapoies kartes/drivers exoun parapanw capabilities pou vohthoun sto rate control ? H kalytera oios tha htan o kalyteros tropos na exoume px. vendor specific algorithmous, opws px. o minstrel (vl madwifi) h oi algorithmoi ths Intel ? Mexri twra oi drivers ths Intel toulaxiston, xrhsimopoioun ton diko tous rate control algorithmo ws ksexwristo module. Meta eipame oti to idaniko tha htan oi algorithmoi na einai meros tou mac80211 kai oxi ekswterikoi kai telika symfwnisame se ena evelikto tropo epiloghs rate control algorithmou apo ton driver, xrhsimopoiwntas capabilities klp, dinontas isws se kapoious drivers th dynatothta na xrhsimopoihsoun kapoion apo tous vendor specific algorithmous an ploiroun ta aparaithta capabilities (p.x. MRR). Ayto vevaia menei na ylopoihthei, prepei kapoios na katsei na dei ton kwdika apo olous tous algorithmous, na kanei to kseskartarisma klp (psinetai kaneis sas ?). ---Various stuff--- Mias pou phgame sthn Ottawa, apofasisame na katsoume kath olh th diarkeia tou OLS, o John Linville (o kernel maintainer gia tous wireless drivers) ekane mia parousiash (BoF) thn opoia mporeite na deite edw -> http://www.kernel.org/pub/linux/kernel/people/linville/ols2008/presentation.pdf, enw eixame kai alles syhtiseis toso mesa to OLS, oso kai ston kafe klp. Genikws perasame yperoxa kai gnwristikame kalytera metaksy mas, hpiame arketes mpyres, xorepsame salsa -enas developer ap' thn Intel xorevei apistefth slasa btw-, fagame mexri skasmou klp. Enas developer ap' to Ubuntu phge kai epekse live (ekane sign se open mike session) se ena magazi ekei konta (me thn carbon fiber ! kithara tou) kai phgame na ton doume (egine anarpastos) opote giname liwma -koimhthikame stis 4 kai mas stamathse ki enas astynomikos sto dromo giati perasame me kokkino stis 3 :P-. Thn teleytaia mera phgame oloi se ena bar pou htan olo gia parth mas (private party + open bar :P) kai ksanaginame liwma (ekei btw eixe kai tis mones sovares mpyres), enw thn Kyriakh sthn Ottawa kleinoun tous dromous to prwi gia podhlata, opote kaname to gyro ths polhs (efaga kai mia kalh savoura :P) kai katalhksame se ena parko opou to ekei lug mas eixe sthsei BBQ ! Htan teleia ! Dystyxws ap' tou xronou katedafizetai to Rideau center opou ginotan mexri twra to OLS alla to synedrio tha metaferthei telika sto Montreal, opote dwsame rantevou gia ekei... Grapsame ligo kwdika sxetika me to CRDA, kaname kapoies syzhtiseis peretairw gia to AP support kai to pws o Jouni, twra pou einai sthn Atheros tha doulepsei arketa se ayto kai syzhthsa me ton Luis kai ton Jouni gia to pws tha kanoume merge ton ath5k me ton ath9k (toulaxiston na mazepsoume ta common kommatia tous). Epishs megalh entyposh ekane h kinhsh ths Atheros me ton ath9k, toso ta paidia ap' thn Intel oso kai apo thn Broadcom eixan meikta synaisthimata, ap' th mia fovountai mia kinhsh ths FCC enantion ths Atheros pou ousiastika tha xtypisei kampanaki kai stis dikes tous etairies kai olh h prospatheia pou ginetai gia na proxwirsoun pros open-source lyseis tha paei strafi (koinws fovountai oti h Atheros prokalese). Ap' thn allh omws an ola pane kala tha exoun poly perissotera epixeirhmata na peisoun kai oi idioi (idiaitera h Broadcom) tis etairies tous pros ayth th kateythynsh. Ena allo thema pou sxedon ekseplhkse einai oti h Marvell fainetai epitelous na asxoleitai me Open Source lyseis, einai sta skaria enas kainourios open-source driver gia tis asyrmates kartes tous, enw gia prwth fora esteilan arketo kosmo sto OLS pou asxoleitai oxi mono me wireless alla kai me alla themata -p.x. proselavan kapoia paidia pou doulevan sto ARM support ston kernel-. Syzhtisame arketa gia ton Network Manager ai diafora themata sxetika me to d-bus, ton wpa_supplicant, to aggregation twn queues sto 802.11n, kathos kai me xrhstes pou eixan apories gia tis kartes tous. Telos kath' olh th diarkeia tou event yphrxan arketes etairies pou ekanan recruit, me thn Intel kai thn Wind River na exoun kleisei thn executive suite (sxedon misos orofos) gi' ayth th douleia. An kapoios apo esas psinetai na asxolhthei me wireless development mporei na stilei cv sth dieythynsh wireless [ at ] linux [ dot ] intel [ dot ] com gia thn intel -oi opoioi ap'oti katalava efygan me adeia xeria giati den vrhkan kosmo- (gia th windriver den thymamai alla logika kati tha leei sto site tous). Epishs kai h Atheros psaxnei kosmo (kyriws gia douleia sthn India) kai h cozybit (h etairia pou doulevei sto 802.11s, sto OLPC klp) psaxei epishs kosmo. Ttha phgaina egw se kapoia (mias pou mou to protinane kai oi 4 :P) alla den exw teleiwsei me th sxolh mou akoma, exw kai to fantariko opote mou einai idiaitera dyskolo se ayth th fash -h Wind River kai h Cozybit pantws mporoun na proslavoun kai gia part time an kapoios endiaferetai-, an kapoios apo esas omws exei asxolhthei sovara me to thema mporw na vohthisw. Ayta apo emena, sorry pou den grafw syxna sth lista alla dystyxws pizw ;-( Kleinontas thelw na eyxaristisw to ergasthrio sto opoio doulevw (http://www.ics.forth.gr/tnl/) pou me vohthise me ta eksoda tou ksenodoxeiou -par olo pou emai pro-ptyxiakis kai h douleia mou ekei den sxetizetai amesa me ton ath5k- kathws kai ton T. Karouno pou me vohthise me ta eishthria (poy htan kai to megalytero kostos). Xwris thn stiriksh tous den tha mporousa na paw sthn Ottawa (kanonika tha eixa sponshorship ap' to Linux foundation alla eixan ena event kapoious mhnes prin kai eixan kseminei, enw to MadWiFi team mou proteine epishs kapoia vohthia alla arnhthika giati ta donations ta exoume gia to testing lab mas). Genikws to oikonomiko einai ena provlhmma, idiaitera otan eisai foithths kai den mporeis na vreis full time douleia logw twn synthikwn. Kalo tha htan na exoume kati poio organomeno giati eimai sigouros oti yparxoun arketa paidia pou theloun na asxolhthoun me antistoixa projects kai na parakolouthisoun kapoia apo ayta ta events alla den eixan thn idia tyxh me emena. Na 'ste oloi kala ki elpizw na sas petyxw se kana mpyro/kafe/masa-meeting. Kalh synexeia sta projects sas ;-) -- GPG ID: 0xD21DB2DB As you read this post global entropy rises. Have Fun ;-) Nick