Chikwata chevaongorori kubva kuPeking University, Tsinghua University uye University of Texas kuDallas kirasi itsva yeDoS kurwisa - RangeAmp, zvichienderana nekushandiswa kweHTTP musoro kuronga kukwidziridzwa kwetraffic kuburikidza nemukati mekuendesa network (CDN). Chinokosha cheiyo nzira ndechekuti nekuda kwenzira iyo misoro yeRange inogadziriswa mumaCDN mazhinji, anorwisa anogona kukumbira imwe byte kubva kufaira hombe kuburikidza neCDN, asi CDN inodhawunirodha faira rese kana bhuroka rakakura kwazvo re data kubva target server kuti iiswe mu cache. Iyo dhigirii yekuwedzera traffic panguva yekurwiswa kwakadaro, zvichienderana neCDN, inotangira pa724 kusvika 43330 nguva, iyo inogona kushandiswa kuremedza iyo CDN neiri kuuya traffic kana kuderedza kugona kweyekupedzisira nzira yekutaurirana kunzvimbo yeakabatwa.
Musoro weRange unopa mutengi kugona kudoma huwandu hwezvinzvimbo mufaira rinofanira kudhaunirodwa pane kudzosera faira rese. Semuenzaniso, mutengi anogona kudoma "Range: bytes=0-1023" uye sevha inongoendesa chete yekutanga 1024 bytes yedata. Iyi ficha iri kudiwa pakurodha mafaera makuru - mushandisi anogona kumbomira kurodha obva aenderera kubva panzvimbo yakavhiringwa. Paunenge uchitsanangura "bytes = 0-0", chiyero chinoraira kupa yekutanga byte mufaira, "bytes = -1" - yekupedzisira, "bytes = 1-" - kutanga kubva pa1 byte kusvika pakupera kwefaira. Zvinogoneka kufambisa akati wandei mumusoro mumwe, semuenzaniso "Range: bytes = 0-1023,8192-10240".
Uyezve, sarudzo yechipiri yekurwisa yakarongedzerwa, inotarisirwa kuwedzera mutoro wetiweki paunenge uchitumira traffic kuburikidza neimwe CDN, iyo inoshandiswa se proxy (semuenzaniso, kana Cloudflare ichiita semberi (FCDN), uye Akamai anoita senge backend ( BCDN). Nzira yacho yakafanana neyokutanga kurwisa, asi inowanikwa mukati meCDN network uye inobvumira kuwedzera kwemotokari kana yasvika kuburikidza nemamwe maCDN, kuwedzera mutoro pazvivakwa uye kuderedza hutano hwebasa.
Pfungwa iri pakuti munhu anorwisa anotumira Range zvikumbiro zvezvikamu zvakati wandei kuCDN, senge "bytes=0-,0-,0-...", "bytes=1-,0-,0-..." kana "mabhayiti=-1024,0 ,0-,0-...". Zvikumbiro zvine nhamba huru ye "0-" mutsara, zvichireva kuti faira inodzorerwa kubva panzvimbo zero kusvika kumagumo. Nekuda kwekusaitwa zvisirizvo kwemhando yekupatsanura, kana CDN yekutanga ikasvika yechipiri, faira rakazara rinotumirwa kune yega yega "53-" renji (iyo mitsara haina kuunganidzwa, asi inoteedzana inodzokororwa), kana paine kudzokororwa uye mharadzano yezvikamu mukati. chikumbiro chakatanga kutumirwa neanorwisa. Iyo dhigirii yekuwedzera kwetraffic mukurwisa kwakadaro kubva pa7432 kusvika kuXNUMX nguva.
Munguva yekudzidza, maitiro e13 CDNs akadzidzwa -
Akamai, Alibaba Cloud, Azure, CDN77, CDNsun, Cloudflare, CloudFront, Fastly, G-Core Labs, Huawei Cloud, KeyCDN, StackPath uye Tencent Cloud. Yese maCDN akaongororwa akabvumira rudzi rwekutanga rwekurwisa pane server yekupedzisira. Musiyano wechipiri wekurwiswa kweCDN wakanganisa masevhisi matanhatu, ayo mana anogona kuita senge pamberi pakurwisa (CDN6, CDNsun, Cloudflare uye StackPath) uye matatu senge backend (Akamai, Azure uye StackPath). Kubudirira kukuru kunowanikwa muAkamai uye StackPath, iyo inobvumira anopfuura zviuru gumi mazinga kuti atsanangurwe muRange musoro. Varidzi veCDN vakaziviswa nezvekusagadzikana kwemwedzi ye77 yapfuura, uye panguva iyo ruzivo rwakaziviswa pachena, gumi nemaviri kubva pagumi nematatu maCDN akange agadzirisa matambudziko akaonekwa kana kuratidza kugadzirira kuzvigadzirisa (chete StackPath sevhisi haina kupindura).
Source: opennet.ru