X-Git-Url: https://git.llucax.com/z.facultad/75.74/practicos.git/blobdiff_plain/325913ed27a683b8a13033aeb8dc693376f4a7dc..78d6e1ce97611abe9f0d083033197773f93c33f7:/practicas/pipi/src/nameserver.cpp

diff --git a/practicas/pipi/src/nameserver.cpp b/practicas/pipi/src/nameserver.cpp
index 3b54140..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))
@@ -177,7 +180,7 @@ 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 +204,21 @@ 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_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;
@@ -221,43 +227,203 @@ 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::cerr << "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::cerr << "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);
     // TODO TTL!?!
     if (i != cache.end())
     {
-        // TODO mandar resultados?
 #ifdef DEBUG_RESOLV
-        std::cerr << "resolv_next found (en cache): " << i->second << "\n";
+        std::cerr << "resolv_direct found (en cache): " << i->second << "\n";
 #endif
-        return;
+        const CacheRecord& cr = i->second;
+        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::cerr << "resolv_next found (al padre): " << zones.front().parent
+            std::cerr << "resolv_direct -> evaluando padre " << i->parent
                 << "\n";
-        return;
 #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!
+        }
     }
-    // TODO enviar NOT FOUND
 #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 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)
@@ -290,8 +456,8 @@ 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, ","));
+    std::copy(cr.ips.begin(), cr.ips.end(),
+            std::ostream_iterator< IPAddr >(os, ","));
     return os << ")";
 }