Kuyesa kwa CacheBrowser: kudutsa chotchingira cha China popanda woyimilira pogwiritsa ntchito caching

Chithunzi: Unsplash

Masiku ano, gawo lalikulu la zonse zomwe zili pa intaneti zimagawidwa pogwiritsa ntchito ma CDN. Nthawi yomweyo, fufuzani momwe ma censor osiyanasiyana amapititsira mphamvu zawo pamanetiweki otere. Asayansi ochokera ku yunivesite ya Massachusetts kusanthula zotheka njira zotsekereza zomwe zili mu CDN pogwiritsa ntchito chitsanzo cha machitidwe a akuluakulu aku China, komanso adapanga chida chodutsira kutsekereza kotere.

Takonzekera zowunikira ndi mfundo zazikulu ndi zotsatira za kuyesaku.

Mau oyamba

Censorship ndikuwopseza padziko lonse lapansi ufulu wolankhula pa intaneti komanso mwayi wodziwa zambiri. Izi zimatheka chifukwa chakuti intaneti idabwereka chitsanzo cha "kulumikizana-kutha-kumapeto" kuchokera kumagulu amafoni a 70s a zaka zapitazo. Izi zimakupatsani mwayi kuti mutseke zopezeka kapena kulumikizana ndi ogwiritsa ntchito popanda khama lalikulu kapena mtengo wongotengera adilesi ya IP. Pali njira zingapo pano, kuyambira kutsekereza adilesi yomwe ili ndi zoletsedwa mpaka kutsekereza kuthekera kwa ogwiritsa ntchito kuti azindikire pogwiritsa ntchito kusintha kwa DNS.

Komabe, kukula kwa intaneti kwadzetsanso njira zatsopano zofalitsira chidziwitso. Chimodzi mwa izo ndikugwiritsa ntchito zinthu zosungidwa kuti zithandizire magwiridwe antchito ndikufulumizitsa kulumikizana. Masiku ano, opereka ma CDN amakonza kuchuluka kwa magalimoto padziko lonse lapansi - Akamai, mtsogoleri wagawo lino, yekhayo amawerengera mpaka 30% ya kuchuluka kwa magalimoto padziko lonse lapansi.

Netiweki ya CDN ndi njira yogawidwa yoperekera zinthu pa intaneti mwachangu kwambiri. Netiweki wamba ya CDN imakhala ndi maseva omwe ali m'malo osiyanasiyana omwe amasunga zinthu kuti azipereka kwa ogwiritsa ntchito omwe ali pafupi kwambiri ndi sevayo. Izi zimakuthandizani kuti muwonjezere kwambiri liwiro la kulumikizana pa intaneti.

Kuphatikiza pa kuwongolera zochitika kwa ogwiritsa ntchito otsiriza, kuchititsa ma CDN kumathandizira opanga zinthu kukulitsa mapulojekiti awo pochepetsa katundu wawo.

Kuletsa zomwe zili mu CDN

Ngakhale kuti kuchuluka kwa magalimoto a CDN kumapanga kale gawo lalikulu lazidziwitso zonse zomwe zimafalitsidwa pa intaneti, palibe kafukufuku wokhudza momwe ma censors padziko lapansi amayendera kuwongolera kwake.

Olemba a phunziroli adayamba pofufuza njira zowunikira zomwe zingagwiritsidwe ntchito ku CDN. Kenako adaphunzira njira zenizeni zomwe akuluakulu aku China amagwiritsa ntchito.

Choyamba, tiyeni tikambirane za njira zotheka censoring ndi kuthekera ntchito kulamulira CDN.

Kusefa kwa IP

Iyi ndiye njira yosavuta komanso yotsika mtengo kwambiri yowonera intaneti. Pogwiritsa ntchito njirayi, censor imazindikiritsa ndikuyika ma adilesi a IP omwe ali ndi zinthu zoletsedwa. Kenako opereka intaneti olamulidwa amasiya kutumiza mapaketi otumizidwa ku ma adilesi oterowo.

IP-based blocking ndi imodzi mwa njira zodziwika kwambiri zowonera intaneti. Zida zambiri zama network zamalonda zili ndi ntchito kuti zitheke kutsekereza kotere popanda kuyeserera kwakukulu.

Komabe, njirayi siyoyenera kwambiri kutsekereza kuchuluka kwa magalimoto a CDN chifukwa cha ukadaulo womwewo:

• Kugawidwa kwa Caching - kuti zitsimikizire kupezeka kwabwino kwa zomwe zili komanso kukhathamiritsa magwiridwe antchito, ma CDN network asungitsa zomwe ogwiritsa ntchito pama seva ambiri am'mphepete omwe ali m'malo omwe amagawidwa. Kuti musefe zinthu zotere kutengera IP, chowunikiracho chimafunika kudziwa maadiresi a ma seva onse am'mphepete ndikuwalemba osalemba. Izi zidzasokoneza zinthu zazikulu za njirayi, chifukwa ubwino wake waukulu ndi wakuti mu ndondomeko yachizolowezi, kutsekereza seva imodzi kumakupatsani mwayi "kudula" kupeza zinthu zoletsedwa kwa anthu ambiri nthawi imodzi.
• Ma IP ogawana - Othandizira a CDN amalonda amagawana zida zawo (ie ma seva a m'mphepete, makina a mapu, etc.) pakati pa makasitomala ambiri. Zotsatira zake, zoletsedwa za CDN zimayikidwa kuchokera ku ma adilesi a IP omwewo monga zomwe sizinaletsedwe. Zotsatira zake, kuyesa kulikonse pa kusefa kwa IP kumapangitsa kuti mawebusayiti ambiri komanso zomwe zilibe chidwi kuti ma censor atsekedwe.
• Ntchito yayikulu kwambiri ya IP - kukhathamiritsa kusanja kwa katundu ndikuwongolera magwiridwe antchito, kupanga mapu a maseva am'mphepete ndi ogwiritsa ntchito kumapeto kumachitika mwachangu komanso mwamphamvu. Mwachitsanzo, zosintha za Akamai zidabweza ma adilesi a IP mphindi iliyonse. Izi zipangitsa kuti zikhale zosatheka kuti ma adilesi azilumikizidwa ndi zinthu zoletsedwa.

Kusokoneza kwa DNS

Kupatula kusefa kwa IP, njira ina yotchuka yowunikira ndi kusokoneza kwa DNS. Njirayi ikuphatikiza zochita ndi ma censors omwe cholinga chake ndi kuletsa ogwiritsa ntchito kuzindikira ma adilesi a IP azinthu zomwe zili ndi zoletsedwa. Ndiko kuti, kulowererapo kumachitika pamlingo wowongolera dzina la domain. Pali njira zingapo zochitira izi, kuphatikiza kubera zolumikizira za DNS, kugwiritsa ntchito njira zakupha za DNS, ndikuletsa zopempha za DNS kumasamba oletsedwa.

Iyi ndi njira yotchinga yothandiza kwambiri, koma imatha kulambalalitsidwa ngati mugwiritsa ntchito njira zosavomerezeka za DNS, mwachitsanzo, njira zakunja. Chifukwa chake, ma censors nthawi zambiri amaphatikiza kutsekereza kwa DNS ndi kusefa kwa IP. Koma, monga tafotokozera pamwambapa, kusefa kwa IP sikothandiza pakuwunika za CDN.

Sefa ndi URL/Mawu Ofunikira pogwiritsa ntchito DPI

Zida zamakono zowunikira ntchito zapaintaneti zitha kugwiritsidwa ntchito kusanthula ma URL enieni ndi mawu osakira m'mapaketi a data. Ukadaulo uwu umatchedwa DPI (deep paketi inspection). Machitidwe oterewa amapeza kutchulidwa kwa mawu oletsedwa ndi zothandizira, pambuyo pake amasokoneza kulankhulana pa intaneti. Zotsatira zake, mapaketi amangogwetsedwa.

Njirayi ndi yothandiza, koma yovuta komanso yogwiritsa ntchito kwambiri chifukwa imafuna kusokoneza mapaketi onse a data omwe amatumizidwa mkati mwa mitsinje ina.

Zomwe zili mu CDN zitha kutetezedwa ku kusefa koteroko mofanana ndi "zokhazikika" - muzochitika zonsezi kugwiritsa ntchito kubisa (ie HTTPS) kumathandiza.

Kuphatikiza pa kugwiritsa ntchito DPI kuti mupeze mawu osakira kapena ma URL azinthu zoletsedwa, zida izi zitha kugwiritsidwa ntchito pakuwunika kwambiri. Njirazi zikuphatikizapo kusanthula kwa chiwerengero cha anthu omwe ali pa intaneti / osagwiritsa ntchito intaneti ndi kusanthula ndondomeko zozindikiritsa. Njirazi ndizogwiritsa ntchito kwambiri ndipo pakadali pano palibe umboni wogwiritsa ntchito ma censors pamlingo wokwanira.

Kudziyesa nokha kwa opereka CDN

Ngati censor ndi boma, ndiye kuti ili ndi mwayi uliwonse woletsa omwe amapereka ma CDN kuti azigwira ntchito m'dzikoli omwe samvera malamulo a m'deralo okhudza kupeza zomwe zili. Kudziletsa sikungathe kutsutsidwa mwanjira iliyonse - choncho, ngati kampani yopereka CDN ili ndi chidwi chogwira ntchito m'dziko linalake, idzakakamizika kutsatira malamulo a m'deralo, ngakhale ataletsa ufulu wolankhula.

Momwe China imawerengera zomwe zili mu CDN

The Great Firewall of China imatengedwa moyenerera kuti ndiyo njira yothandiza kwambiri komanso yapamwamba kwambiri yowonetsetsa kuwunika kwa intaneti.

Njira zofufuzira

Asayansi adayesa pogwiritsa ntchito node ya Linux yomwe ili mkati mwa China. Analinso ndi makompyuta angapo kunja kwa dzikolo. Choyamba, ofufuzawo adafufuza kuti mfundoyi imayang'aniridwa mofanana ndi ogwiritsa ntchito ena achi China - kuti achite izi, adayesa kutsegula malo osiyanasiyana oletsedwa kuchokera ku makina awa. Chifukwa chake kukhalapo kwa mulingo womwewo wa censorship kunatsimikiziridwa.

Mndandanda wamawebusayiti oletsedwa ku China omwe amagwiritsa ntchito ma CDN adatengedwa ku GreatFire.org. Njira yotsekera muzochitika zilizonse idawunikidwa.

Malinga ndi zidziwitso zapagulu, wosewera wamkulu yekha pamsika wa CDN wokhala ndi zida zake ku China ndi Akamai. Othandizira ena omwe akuchita nawo phunziroli: CloudFlare, Amazon CloudFront, EdgeCast, Fastly ndi SoftLayer.

Pakuyesa, ofufuzawo adapeza ma adilesi a ma seva am'mphepete mwa Akamai m'dzikolo, kenako adayesa kusungitsa zomwe zimaloledwa kudzera mwa iwo. Sizinali zotheka kupeza zoletsedwa (HTTP 403 Cholakwika Choletsedwa chinabwezedwa) - mwachiwonekere kampaniyo ikudziyesa yokha kuti ikhalebe ndi mphamvu zogwira ntchito m'dzikoli. Pa nthawi yomweyi, mwayi wopeza zinthuzi udali wotseguka kunja kwa dziko.

Ma ISPs opanda zomangamanga ku China sadziyesa okha ogwiritsa ntchito am'deralo.

Pankhani ya opereka ena, njira yotsekereza yomwe imagwiritsidwa ntchito kwambiri inali kusefa kwa DNS - zopempha kumasamba otsekedwa zimathetsedwa kukhala ma adilesi olakwika a IP. Panthawi imodzimodziyo, chowotcha moto sichimalepheretsa ma seva a CDN okha, chifukwa amasunga zonse zoletsedwa komanso zololedwa.

Ndipo ngati pa nkhani ya magalimoto osadziwika olamulira amatha kuletsa masamba amasamba omwe amagwiritsa ntchito DPI, ndiye kuti akamagwiritsa ntchito HTTPS amatha kukana kulowa nawo dera lonselo. Izi zimabweretsanso kutsekeka kwa zinthu zololedwa.

Kuphatikiza apo, China ili ndi othandizira ake a CDN, kuphatikiza maukonde monga ChinaCache, ChinaNetCenter ndi CDNetworks. Makampani onsewa amatsatira kwathunthu malamulo adziko ndikuletsa zomwe zili zoletsedwa.

CacheBrowser: Chida cha CDN chodutsa

Monga momwe kuwunika kwawonetsera, ndizovuta kuti owerengera aletse zomwe zili mu CDN. Chifukwa chake, ofufuzawo adaganiza zopitira patsogolo ndikupanga chida chodutsa pa intaneti chomwe sichigwiritsa ntchito ukadaulo wa proxy.

Lingaliro loyambirira lachidacho ndikuti ma censors amayenera kusokoneza ma DNS kuti atseke ma CDN, koma simuyenera kugwiritsa ntchito dzina la domain kuti mutsitse zomwe zili mu CDN. Chifukwa chake, wogwiritsa ntchito amatha kupeza zomwe akufuna polumikizana mwachindunji ndi seva yam'mphepete, pomwe idasungidwa kale.

Chithunzi chomwe chili pansipa chikuwonetsa kapangidwe kake.

Mapulogalamu a kasitomala amayikidwa pa kompyuta ya wogwiritsa ntchito, ndipo osatsegula wamba amagwiritsidwa ntchito kuti apeze zomwe zili.

Ulalo kapena gawo likafunsidwa kale, msakatuli amapempha ku DNS system (LocalDNS) kuti apeze adilesi ya IP. DNS wanthawi zonse amafunsidwa pamadomeni omwe mulibe kale munkhokwe ya LocalDNS. The Scraper module mosalekeza imadutsa ma URL omwe akufunsidwa ndikufufuza mndandanda wa mayina omwe angakhale otsekedwa. Scraper ndiye amayitanitsa gawo la Resolver kuti athetse madera otsekedwa kumene, gawoli limagwira ntchitoyo ndikuwonjezera kulowa kwa LocalDNS. Cache ya DNS ya msakatuliyo imachotsedwa kuti achotse zolembedwa za DNS zomwe zidatsekedwa.

Ngati gawo la Resolver silingathe kudziwa kuti ndi ndani yemwe amapereka ma CDN omwe ali nawo, adzafunsa gawo la Bootstrapper kuti athandizidwe.

Momwe zimagwirira ntchito

Pulogalamu yamakasitomala yazinthuzo idakhazikitsidwa ku Linux, koma imatha kutumizidwanso pa Windows. Mozilla wamba amagwiritsidwa ntchito ngati msakatuli
Firefox. Ma modules a Scraper ndi Resolver amalembedwa mu Python, ndipo Customer-to-CDN ndi CDN-toIP databases amasungidwa mu .txt mafayilo. Dongosolo la LocalDNS ndi fayilo yanthawi zonse /etc/hosts mu Linux.

Zotsatira zake, kwa URL yotsekedwa ngati blocked.com Cholembacho chidzapeza adilesi ya IP ya seva kuchokera pa /etc/hosts file ndikutumiza pempho la HTTP GET kuti mupeze BlockedURL.html ndi minda yamutu ya Host HTTP:

blocked.com/ and User-Agent: Mozilla/5.0 (Windows
NT 5.1; rv:14.0) Gecko/20100101 Firefox/14.0.1

Module ya Bootstrapper imayendetsedwa pogwiritsa ntchito chida chaulere digwebinterface.com. Wokonza DNS uyu sangathe kutsekedwa ndipo amayankha mafunso a DNS m'malo mwa ma seva angapo a DNS omwe amagawidwa m'magawo osiyanasiyana.

Pogwiritsa ntchito chida ichi, ochita kafukufuku adatha kupeza Facebook kuchokera ku malo awo achi China, ngakhale kuti malo ochezera a pa Intaneti adatsekedwa ku China.

Pomaliza

Kuyeseraku kunawonetsa kuti kugwiritsa ntchito mwayi pamavuto omwe owunikira amakumana nawo poyesa kuletsa zomwe zili mu CDN zitha kugwiritsidwa ntchito kupanga njira yodutsa midadada. Chida ichi chimakulolani kuti mulambalale midadada ngakhale ku China, yomwe ili ndi imodzi mwazinthu zamphamvu kwambiri zowunikira pa intaneti.

Nkhani zina pamutu wogwiritsa ntchito ma proxies okhala za bizinesi:

• Momwe ma proxies okhalamo amathandizira mubizinesi: nkhani yeniyeni yogwiritsira ntchito Infatica m'munda wa Data Mining
• Kusanthula. Kodi woyimira SOCKS amagwira ntchito bwanji: zabwino, zoyipa, zosiyana ndi matekinoloje ena
• Momwe mungasankhire ma proxy network pabizinesi: Malangizo 3 othandiza

Source: www.habr.com