X-Git-Url: https://git.llucax.com/z.facultad/75.74/practicos.git/blobdiff_plain/384545ce291041b819661bf6d66b00e4c8ee88fd..HEAD:/practicas/pipi/src/nameserver.cpp diff --git a/practicas/pipi/src/nameserver.cpp b/practicas/pipi/src/nameserver.cpp index 45ec63d..4fd894a 100644 --- a/practicas/pipi/src/nameserver.cpp +++ b/practicas/pipi/src/nameserver.cpp @@ -8,8 +8,6 @@ #include #endif -#define DEBUG_RESOLV - NameServer::Name::Name(const std::string& s) { std::istringstream iss(s); @@ -27,7 +25,7 @@ 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; @@ -48,7 +46,7 @@ static std::istream& parsezone(std::istream& is, NameServer::Zone& z) throw std::runtime_error("Error al parsear"); z.name = sname; #ifdef DEBUG_PARSER - std::cerr << "parsezone: IP = " << ip << "\n\n"; + std::cout << "NameServer::parsezone: IP = " << ip << "\n\n"; #endif z.parent = IPAddr(ip); // un record por linea, sin líneas vacías @@ -62,13 +60,13 @@ static std::istream& parsezone(std::istream& is, NameServer::Zone& z) throw std::runtime_error("Error al parsear"); typedef NameServer::Record Rec; #ifdef DEBUG_PARSER - std::cerr << "parsezone: IP = " << ip << "\n\n"; + std::cout << "NameServer::parsezone: IP = " << ip << "\n\n"; #endif Rec r((type == "NS") ? Rec::NS : Rec::A, IPAddr(ip)); z.records.insert(NameServer::Zone::records_t::value_type(key, r)); } #ifdef DEBUG_PARSER - std::cerr << "parsezone: " << z << "\n\n"; + std::cout << "NameServer::parsezone: " << z << "\n\n"; #endif return is; } @@ -96,8 +94,11 @@ 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)) @@ -105,9 +106,15 @@ NameServer::NameServer(std::istream& is) zones.push_back(z); z.clear(); #ifdef DEBUG_PARSER - std::cerr << "NameServer: " << z << "\n\n"; + std::cout << "NameServer::NameServer: " << z << "\n\n"; #endif } + +#ifdef DEBUG_RESOLV + std::cout << "NameServer::NameServer: req_que_id = " << req_que.que_id + << ", res_que_id = " << res_que.que_id + << ", snd_que_id = " << snd_que.que_id << "\n"; +#endif } /// Devuelve la parte izquierda de n, si la parte derecha coincide exactamente @@ -135,7 +142,8 @@ name_split(NameServer::Name n, NameServer::Name m) r.push_back(n[i++]); std::reverse(r.begin(), r.end()); #ifdef DEBUG_NAME - std::cerr << "name_split(" << n << ", " << m << ") -> " << r << "\n"; + std::cout << "NameServer::name_split(" << n << ", " << m << ") -> " + << r << "\n"; #endif return r; } @@ -177,7 +185,7 @@ static int name_cmp(const NameServer::Name& n, const NameServer::Name& m) struct search_zone: std::unary_function< NameServer::Zone, bool > { bool local; - NameServer::CacheRecord crecord; + ResolvProtoResponse resp; const NameServer::Name& name; search_zone(const NameServer::Name& n): local(false), name(n) {} bool operator() (const NameServer::Zone& z) @@ -201,18 +209,25 @@ struct search_zone: std::unary_function< NameServer::Zone, bool > if ((local_part.size() > 1) && r.type != NameServer::Record::NS) continue; found = true; - crecord.ttl = z.ttl; - crecord.records.push_back(r); + resp.ret = (r.type == NameServer::Record::NS) ? RP_RES_NS + : RP_RES_A; + resp.ttl = z.ttl; + resp.ips.push_back(r.ip); } } return found; } }; -void NameServer::resolv_next(const Name& n) +/// Resuelve un nombre de forma directa (no recursiva) +ResolvProtoResponse NameServer::resolv_direct(const Name& n) { +#ifdef DEBUG_TRACE + std::cout << "NameServer::resolv_direct()\n"; +#endif #ifdef DEBUG_RESOLV - std::cerr<< "resolv_next -> tratando de resolver: " << n << "\n"; + std::cout << "NameServer::resolv_direct -> tratando de resolver: " + << n << "\n"; #endif search_zone zs(n); bool found; @@ -221,42 +236,246 @@ void NameServer::resolv_next(const Name& n) break; if (found) { - // TODO mandar resultados? #ifdef DEBUG_RESOLV - std::cerr<< "resolv_next found (local/hijo): " << zs.crecord << "\n"; + std::cout << "NameServer::resolv_direct -> found (local/hijo): " + << zs.resp << "\n"; #endif - return; + return zs.resp; } if (zs.local) { - // TODO mandar NOT FOUND #ifdef DEBUG_RESOLV - std::cerr<< "resolv_next NOT FOUND (es local pero no existe)\n"; + std::cout << "NameServer::resolv_direct -> NOT FOUND (es local pero " + "no existe)\n"; #endif - return; + return ResolvProtoResponse(RP_RES_NOTFOUND); } - cache_t::const_iterator i = cache.find(n); + cache_t::iterator i = cache.find(n); if (i != cache.end()) { - // TODO mandar resultados? + const CacheRecord& cr = i->second; #ifdef DEBUG_RESOLV - std::cerr<< "resolv_next found (en cache): " << i->second << "\n"; + std::cout << "NameServer::resolv_direct -> found (en cache): " + << cr << "\n"; #endif - return; + if (unsigned(time(NULL)) > cr.expire) // Expiró + { + cache.erase(i); +#ifdef DEBUG_RESOLV + std::cout << " -> pero no sirve, expiró " + "hace unos " << (time(NULL) - cr.expire) << " segundos\n"; +#endif + } + else + { + return ResolvProtoResponse(RP_RES_A, cr.ttl, cr.ips); + } } - // TODO enviar nameserver padre, si no hay padre, mandar NOT FOUND 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::cout << "NameServer::resolv_direct -> evaluando padre " + << i->parent << "\n"; +#endif + if (i->parent != IPAddr(0)) + { #ifdef DEBUG_RESOLV - std::cerr << "resolv_next found (al padre): " << zones.front().parent - << "\n"; - return; + std::cout << "NameServer::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::cout << "NameServer::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) +{ +#ifdef DEBUG_TRACE + std::cout << "NameServer::resolv_recursive()\n"; +#endif + ResolvProtoResponse rpr = resolv_direct(n); + switch (rpr.ret) + { + case RP_RES_NS: +#ifdef DEBUG_RESOLV + std::cout << "NameServer::resolv_recursive -> redirect a " + << rpr << "\n"; +#endif + return resolv_recursive_r(n, rpr); // Sigo "bajando" + case RP_RES_A: +#ifdef DEBUG_RESOLV + std::cout << "NameServer::resolv_recursive -> gotcha! " + << rpr << "\n"; +#endif + 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) +{ +#ifdef DEBUG_TRACE + std::cout << "NameServer::resolv_recursive_r()\n"; +#endif + 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::cout << "NameServer::resolv_recursive_r -> redirect a " + << r << "\n"; +#endif + return resolv_recursive_r(n, r); // Sigo "bajando" + case RP_RES_NOTFOUND: +#ifdef DEBUG_RESOLV + std::cout << "NameServer::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::cout << "NameServer::resolv_recursive_r -> gotcha! " + << r << "\n"; +#endif + return r; // Gotcha! + } } - // TODO enviar NOT FOUND #ifdef DEBUG_RESOLV - std::cerr<< "resolv_next NOT FOUND (no hay padre)\n"; + std::cout << "NameServer::resolv_recursive_r -> NOT FOUND, no hay más " + "por hacer\n"; #endif + return r; // NOTFOUND +} + +/// Consulta a otro name server sobre un nombre +ResolvProtoResponse NameServer::query(const Name& n, const IPAddr& ip) +{ +#ifdef DEBUG_TRACE + std::cout << "NameServer::query()\n"; +#endif + ResolvProtoRequest r(std::string(n), RP_REQ_DIRECT); +#ifdef DEBUG_RESOLV + std::cout << "NameServer::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::cout << "NameServer::query -> recibido " << resp << " de " + << ip << "\n"; +#endif + // Agrego a cache + if (resp.ret == RP_RES_A) + cache[n] = CacheRecord(time(NULL) + resp.ttl, resp.ttl, resp.ips); + return resp; +} + +void NameServer::recv_loop() +{ +#ifdef DEBUG_TRACE + std::cout << "NameServer::recv_loop()\n"; +#endif + 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.data(), 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() +{ +#ifdef DEBUG_TRACE + std::cout << "NameServer::send_loop()\n"; +#endif + while (true) + { + Dev::mac_type mac = 0; + std::string buf = snd_que.receive(mac); +#ifdef DEBUG_RESOLV + uint8_t type; + memcpy(&type, buf.data(), sizeof(uint8_t)); + std::cout << "NameServer::send_loop() -> envío "; + if (type == RP_REQ_DIRECT || type == RP_REQ_RECURSIVE) + std::cout << "request " << ResolvProtoRequest(buf) << "\n"; + else + std::cout << "response " << ResolvProtoResponse(buf) << "\n"; +#endif + ipout.send(buf, RESOLV_PROTO, IPAddr(mac)); + } +} + +void NameServer::req_loop() +{ +#ifdef DEBUG_TRACE + std::cout << "NameServer::req_loop()\n"; +#endif + while (true) + { +#ifdef DEBUG_RESOLV + std::cout << "----------------------------------------------------\n"; +#endif + Dev::mac_type mac = 0; + ResolvProtoRequest req(req_que.receive(mac)); +#ifdef DEBUG_RESOLV + std::cout << "NameServer::req_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::req_loop() -> respondo " << res << "\n"; +#endif + snd_que.transmit(std::string(res), IPAddr(mac)); + } } std::ostream& operator<< (std::ostream& os, const NameServer::Record::type_t& t) @@ -288,9 +507,10 @@ std::ostream& operator<< (std::ostream& os, const NameServer::Zone& z) std::ostream& operator<< (std::ostream& os, const NameServer::CacheRecord& cr) { - os << "CacheRecord(ttl=" << cr.ttl << ", records="; - std::copy(cr.records.begin(), cr.records.end(), - std::ostream_iterator< NameServer::Record >(os, ",")); + os << "CacheRecord(expire=" << cr.expire << " [now=" << time(NULL) + << "], ttl=" << cr.ttl << ", records="; + std::copy(cr.ips.begin(), cr.ips.end(), + std::ostream_iterator< IPAddr >(os, ",")); return os << ")"; }