TCP Zero Window iyada oo loo marayo proxy: aqoonsi qaataha

Go'aami halka xakamaynta qulqulka TCP ku taal dhinaca macmiilka ama server-ka proxy ka hor inta aadan u nisbayn soo dejinta istaagtay window scaling ama cabbirka buffer-ka.

Raadraac packet ah ayaa sheegaya TCP ZeroWindow. Ka hor inta aadan beddelin dejinta kernel-ka, aqoonso endpoint-ka soo bandhigaya eber.

Endpoint-kaas wuxuu sharraxayaa awooddiisa qaadashada ee isku xirka TCP-kan. Ma aha inuu sheegayo inta bandwidth ee proxy-ga oo dhan uu hayo. Probe-ka zero-window wuxuu u oggolaanayaa dirkta inay ogaato haddii awoodda la sheegay is beddeshay; probe-ka keligiis ma caddeeyo luminta packet-ka ama proxy xun.

browser  <-- TCP A -->  proxy  <-- TCP B -->  website

Kuwani waa laba wada-hadal TCP oo gooni ah. Ka soo qaad in browser-ku joojiyo akhrinta jawaab weyn oo uu eber ku dhawaaqo A. Proxy-gu wuxuu ugu dambayn joojin karaa ka-soo-baxa B marka buffer-kiisa buuxsamo. Zero window dambe oo B ku yimaada waxa laga yaabaa inuu natiijo ka yimaado macmiilka gaabis ah halkii uu ahaan lahaa dhibaatada asalka ah.

Xaaladda lidka ku ah waxay dhici kartaa inta la soo gelinayo. Haddii barnaamijka loo socdo joojiyo isticmaalka xogta, window-kiisa B wuu xirmi karaa. Cadaadisku wuxuu markaas dib ugu noqon karaa dhanka macmiilka isagoo maraya buffer-yada proxy-ga.

U dhig indha-indhaynta nidaam

  1. Qor endpoint-yada isku xirka iyo jihada wareejinta xogta la saameeyay.
  2. Aqoonso endpoint-ka ugu horreeya ee soo bandhigay receive window yaraatay ama eber noqotay.
  3. Hubi haddii barnaamijkiisu akhrinayay, ku hakaday hawl kale, ama xaddidan yahay kheyraad.
  4. Isbarbardhig waqtiga isku xirka kale ee proxy-ga ka hor intaadan go'aamin sababta asalka ah.

Calaamadaha falanqaynta window ee Wireshark waa tafsiirro faa'iido leh oo ku saabsan duubista, ma aha tilmaan ah in la kordhiyo receive buffer kasta. Window scaling sidoo kale waa in lagu tafsiiraa iyadoo la eegayo wada-xaajoodka isku xirka.

Isku day endpoint kale oo ka mid ah liiska proxy oo arag in wareejintu soo kabsatay waa caddayn faa'iido leh in dariiquu beddelmay. Taasi keligeed ma caddeyso in hal nidaam hawleed oo TCP ah uu cillad lahaa. Sharaxaadda ku xidh habka qaataha iyo isku xirka ay sugitaanku ka bilaabmay.

Maqaallo la xiriira