X-Git-Url: https://git.llucax.com/z.facultad/75.74/practicos.git/blobdiff_plain/c048ca1252065d6705763043eb2ff750d95e52e9..78d6e1ce97611abe9f0d083033197773f93c33f7:/practicas/pipi/src/nameserver.cpp diff --git a/practicas/pipi/src/nameserver.cpp b/practicas/pipi/src/nameserver.cpp index 1e6e19c..b007975 100644 --- a/practicas/pipi/src/nameserver.cpp +++ b/practicas/pipi/src/nameserver.cpp @@ -27,7 +27,7 @@ std::ostream& operator<< (std::ostream& os, const NameServer::Name& name) return os << name.back(); } -NameServer::Name::operator std::string () +NameServer::Name::operator std::string () const { std::stringstream ss; ss << *this; @@ -96,8 +96,11 @@ void NameServer::Zone::clear() } /// Constructor -NameServer::NameServer(std::istream& is) - throw (std::runtime_error) +NameServer::NameServer(std::istream& is, IPIn& ipin, IPOut& ipout, + DevQue& req_que, DevQue& res_que, DevQue& snd_que) + throw (std::runtime_error): + ipin(ipin), ipout(ipout), req_que(req_que), res_que(res_que), + snd_que(snd_que) { Zone z; while (parsezone(is, z)) @@ -201,8 +204,8 @@ struct search_zone: std::unary_function< NameServer::Zone, bool > if ((local_part.size() > 1) && r.type != NameServer::Record::NS) continue; found = true; - resp.ret = (r.type == NameServer::Record::NS) - ? ResolvProtoResponse::R_NS : ResolvProtoResponse::R_A; + resp.ret = (r.type == NameServer::Record::NS) ? RP_RES_NS + : RP_RES_A; resp.ttl = z.ttl; resp.ips.push_back(r.ip); } @@ -211,10 +214,11 @@ struct search_zone: std::unary_function< NameServer::Zone, bool > } }; -ResolvProtoResponse NameServer::resolv_next(const Name& n) +/// Resuelve un nombre de forma directa (no recursiva) +ResolvProtoResponse NameServer::resolv_direct(const Name& n) { #ifdef DEBUG_RESOLV - std::cerr << "resolv_next -> tratando de resolver: " << n << "\n"; + std::cerr << "resolv_direct -> tratando de resolver: " << n << "\n"; #endif search_zone zs(n); bool found; @@ -224,41 +228,202 @@ ResolvProtoResponse NameServer::resolv_next(const Name& n) if (found) { #ifdef DEBUG_RESOLV - std::cerr << "resolv_next found (local/hijo): " << zs.resp << "\n"; + std::cerr << "resolv_direct found (local/hijo): " << zs.resp << "\n"; #endif return zs.resp; } if (zs.local) { #ifdef DEBUG_RESOLV - std::cerr << "resolv_next NOT FOUND (es local pero no existe)\n"; + std::cerr << "resolv_direct NOT FOUND (es local pero no existe)\n"; #endif - return ResolvProtoResponse(ResolvProtoResponse::R_NOTFOUND); + return ResolvProtoResponse(RP_RES_NOTFOUND); } cache_t::const_iterator i = cache.find(n); // TODO TTL!?! if (i != cache.end()) { #ifdef DEBUG_RESOLV - std::cerr << "resolv_next found (en cache): " << i->second << "\n"; + std::cerr << "resolv_direct found (en cache): " << i->second << "\n"; #endif const CacheRecord& cr = i->second; - return ResolvProtoResponse(ResolvProtoResponse::R_A, cr.ttl, cr.ips); + return ResolvProtoResponse(RP_RES_A, cr.ttl, cr.ips); } if (zones.size()) { + // Busco una zona con padre para ver si puedo "trepar" + for (zones_t::const_iterator i = zones.begin(); i != zones.end(); ++i) + { #ifdef DEBUG_RESOLV - std::cerr << "resolv_next found (al padre): " << zones.front().parent + std::cerr << "resolv_direct -> evaluando padre " << i->parent << "\n"; - ResolvProtoResponse rpr(ResolvProtoResponse::R_NS, zones.front().ttl); - rpr.ips.push_back(zones.front().parent); - return rpr; #endif + if (i->parent != IPAddr(0)) + { +#ifdef DEBUG_RESOLV + std::cerr << "resolv_direct found (al padre): " + << i->parent << "\n"; +#endif + ResolvProtoResponse rpr(RP_RES_NS, i->ttl); + rpr.ips.push_back(i->parent); + return rpr; + } + } + } +#ifdef DEBUG_RESOLV + std::cerr << "resolv_direct NOT FOUND (no hay padre)\n"; +#endif + // No hay padre, no puedo hacer nada más + return ResolvProtoResponse(RP_RES_NOTFOUND); +} + +/// Resuelve un nombre de forma recursiva +ResolvProtoResponse NameServer::resolv_recursive(const Name& n) +{ + ResolvProtoResponse rpr = resolv_direct(n); + switch (rpr.ret) + { + case RP_RES_NS: +#ifdef DEBUG_RESOLV + std::cerr << "resolv_recursive -> redirect a " << rpr << "\n"; +#endif + return resolv_recursive_r(n, rpr); // Sigo "bajando" + case RP_RES_A: +#ifdef DEBUG_RESOLV + std::cerr << "resolv_recursive -> gotcha! " << rpr << "\n"; +#endif + // TODO agregar a cache + break; + } + return rpr; // Devuelvo el A o NOTFOUND +} + +/// Resuelve un nombre de forma recursiva entrando a otros ns +ResolvProtoResponse NameServer::resolv_recursive_r(const Name& n, + ResolvProtoResponse rpr) +{ + ResolvProtoResponse r; + for (ResolvProtoResponse::ipvec_t::const_iterator ip = rpr.ips.begin(); + ip != rpr.ips.end(); ++ip) + { + r = query(n, *ip); + switch (r.ret) + { + case RP_RES_NS: +#ifdef DEBUG_RESOLV + std::cerr << "resolv_recursive_r -> redirect a " << r << "\n"; +#endif + return resolv_recursive_r(n, r); // Sigo "bajando" + case RP_RES_NOTFOUND: +#ifdef DEBUG_RESOLV + std::cerr << "resolv_recursive_r -> NOT FOUND en " << *ip + << ", sigo probando\n"; +#endif + break; // Sigo probando del mismo nivel + case RP_RES_A: +#ifdef DEBUG_RESOLV + std::cerr << "resolv_recursive_r -> gotcha! " << r << "\n"; +#endif + // TODO agregar a cache + return r; // Gotcha! + } } #ifdef DEBUG_RESOLV - std::cerr << "resolv_next NOT FOUND (no hay padre)\n"; + std::cerr << "resolv_recursive_r -> NOT FOUND, no hay más por hacer\n"; #endif - return ResolvProtoResponse(ResolvProtoResponse::R_NOTFOUND); + return r; // NOTFOUND +} + +/// Consulta a otro name server sobre un nombre +ResolvProtoResponse NameServer::query(const Name& n, const IPAddr& ip) +{ + ResolvProtoRequest r(std::string(n), RP_REQ_DIRECT); +#ifdef DEBUG_RESOLV + std::cerr << "query -> pidiendo " << r << " a " << ip << "\n"; +#endif + // Envía a través de la cola de envío + snd_que.transmit(std::string(r), ip); + Dev::mac_type mac = ip; + std::string buf = res_que.receive(mac); + ResolvProtoResponse resp(buf); +#ifdef DEBUG_RESOLV + std::cerr << "query -> recibido " << resp << " de " << ip << "\n"; +#endif + return resp; +} + +void NameServer::recv_loop() +{ + while (true) + { + IPAddr src, dst; + uint8_t proto; + std::string s = ipin.recv(proto, src, dst); +#ifdef DEBUG_RESOLV + std::cout << "NameServer::recv_loop() -> recibido len=" << s.size() + << " de " << src << " para " << dst << " (proto = " + << unsigned(proto) << ")\n"; +#endif + if (proto == RESOLV_PROTO) // Si es para nosotros + { + rp_pkt_type_t type; + memcpy(&type, s.c_str(), sizeof(uint8_t)); + switch (type) + { + // Request + case RP_REQ_DIRECT: + case RP_REQ_RECURSIVE: +#ifdef DEBUG_RESOLV + std::cout << "---> " << ResolvProtoRequest(s) << "\n"; +#endif + req_que.transmit(s, src); // Encolo + break; + // Response + default: +#ifdef DEBUG_RESOLV + std::cout << "---> " << ResolvProtoResponse(s) << "\n"; +#endif + res_que.transmit(s, src); // Encolo + } + } + } +} + +void NameServer::send_loop() +{ + while (true) + { + if (!req_que.empty()) + { + Dev::mac_type mac = 0; + ResolvProtoRequest req(req_que.receive(mac)); +#ifdef DEBUG_RESOLV + std::cout << "NameServer::send_loop() -> recibido " << req << "\n"; +#endif + ResolvProtoResponse res + = (req.query_type == RP_REQ_DIRECT) + ? resolv_direct(req.name) + : resolv_recursive(req.name); +#ifdef DEBUG_RESOLV + std::cout << "NameServer::send_loop() -> respondo " << res << "\n"; +#endif + ipout.send(res, RESOLV_PROTO, IPAddr(mac)); + } + else if (!snd_que.empty()) // Hay un request para enviar + { + Dev::mac_type mac = 0; + std::string buf = snd_que.receive(mac); +#ifdef DEBUG_RESOLV + std::cout << "NameServer::send_loop() -> envío request " + << ResolvProtoRequest(buf) << "\n"; +#endif + ipout.send(buf, RESOLV_PROTO, IPAddr(mac)); + } + else // No hay nada, esperamos un rato + { + usleep(10000); + } + } } std::ostream& operator<< (std::ostream& os, const NameServer::Record::type_t& t)