| 1 | {"version":3,"file":"dragon.js","sourceRoot":"","sources":["dragon.ts"],"names":[],"mappings":";;AACA,uCAAsD;AACtD,MAAM,GAAG,GAAG,YAAY,CAAC,QAAQ,CAAC,CAAA;AAClC,yCAA0D;AA6B1D,SAAgB,eAAe,CAC7B,YAAoC,EACpC,WAAyC,EACzC,MAAc,EACd,KAAY;IAGZ,KAAK,MAAM,YAAY,IAAI,YAAY,CAAC,iBAAiB,CAAC,MAAM,CAAC,EAAE;QACjE,MAAM,iBAAiB,GAAG,YAAY,CAAC,GAAG,CAAC,YAAY,CAAC,CAAA;QAExD,IAAI,CAAC,iBAAiB,IAAI,CAAC,iBAAiB,CAAC,KAAK,EAAE;YAClD,GAAG,CAAC,IAAI,CAAC,iGAAiG,EAAE,MAAM,EAAE,YAAY,CAAC,CAAA;YACjI,SAAQ;SACT;QAED,MAAM,WAAW,GAAG,iBAAiB,CAAC,KAAK,CAAA;QAE3C,IAAI,WAAW,CAAC,OAAO,KAAK,EAAE,EAAE;YAE9B,SAAQ;SACT;QAED,MAAM,cAAc,GAAG,WAAW,CAAC,WAAW,CAAC,OAAO,CAAC,CAAA;QACvD,MAAM,aAAa,GAAG,WAAW,CAAC,KAAK,CAAC,OAAO,CAAC,CAAA;QAChD,IAAI,8BAAmB,CAAC,cAAc,CAAC,GAAG,8BAAmB,CAAC,aAAa,CAAC,EAAE;YAE5E,SAAQ;SACT;QAED,GAAG,CAAC,KAAK,CAAC,wDAAwD,EAAE,MAAM,EAAE,YAAY,CAAC,CAAA;QACzF,OAAO,IAAI,CAAA;KACZ;IAED,OAAO,KAAK,CAAA;AACd,CAAC;AAlCD,0CAkCC","sourcesContent":["import { Route } from '../types/routing'\nimport { create as createLogger } from '../common/log'\nconst log = createLogger('dragon')\nimport { Relation, getRelationPriority } from './relation'\nimport ForwardingRoutingTable from '../services/forwarding-routing-table'\n\n/**\n * Check whether a route can be filtered out based on DRAGON rules.\n *\n * See http://route-aggregation.net/.\n *\n * The basic idea is that if we have a more general route that is as good as a\n * more specific route, we don't need to advertise the more specific route.\n *\n * This removes a lot of routing updates across a large network and has basically\n * no downside.\n *\n * Note that we use DRAGON filtering, but *not* DRAGON aggregation. There are\n * several reasons for this:\n *\n * * ILP address space is a lot less dense than IPv4 address space, so\n * DRAGON aggregation would not be a significant optimization.\n *\n * * We may want to secure our routing protocol using a mechanism similar to\n * BGPsec, which precludes aggregation.\n *\n * * We will recommend that owners of tier-1 ILP address space are also real\n * connectors which participate in the routing protocol and originate a route\n * advertisement for their tier-1 prefix. This will enable DRAGON filtering\n * to apply to a lot more situations where otherwise only DRAGON aggregation\n * would be applicable.\n */\nexport function canDragonFilter (\n routingTable: ForwardingRoutingTable,\n getRelation: (prefix: string) => Relation,\n prefix: string,\n route: Route\n): boolean {\n // Find any less specific route\n for (const parentPrefix of routingTable.getKeysPrefixesOf(prefix)) {\n const parentRouteUpdate = routingTable.get(parentPrefix)\n\n if (!parentRouteUpdate || !parentRouteUpdate.route) {\n log.warn('found a parent prefix, but no parent route; this should never happen. prefix=%s parentPrefix=%s', prefix, parentPrefix)\n continue\n }\n\n const parentRoute = parentRouteUpdate.route\n\n if (parentRoute.nextHop === '') {\n // We are the origin of the parent route, cannot DRAGON filter\n continue\n }\n\n const parentRelation = getRelation(parentRoute.nextHop)\n const childRelation = getRelation(route.nextHop)\n if (getRelationPriority(parentRelation) < getRelationPriority(childRelation)) {\n // The more specific route is better for us, so we keep it\n continue\n }\n\n log.trace('applied DRAGON route filter. prefix=%s parentPrefix=%s', prefix, parentPrefix)\n return true\n }\n\n return false\n}\n"]} |