Forwarding casi implementado. Hay un bug cuando se usan distintos MTU que hay

[z.facultad/75.74/practicos.git] / practicas / pipi / src / ipout.cpp

diff --git a/practicas/pipi/src/ipout.cpp b/practicas/pipi/src/ipout.cpp
index e7e211ba49b357ca9db3cf53eea62ff475ed2da9..cf5c28c905a23a895316a89e9435d89a6f371815 100644 (file)
--- a/practicas/pipi/src/ipout.cpp
+++ b/practicas/pipi/src/ipout.cpp
@@ -2,10 +2,15 @@
 #include "ipout.h"
 #include "ipheader.h"
 #include <ctime>
+#include <unistd.h>
+#include <fcntl.h>
+#include <sys/types.h>
+#include <sys/ipc.h>
+#include <sys/msg.h>
 
 /// Constructor
-IPOut::IPOut(const IPAddr& ip, RouteTable& rtable, std::ostream& log):
-    ip(ip), rtable(rtable), log(log)
+IPOut::IPOut(const IPAddr& ip, RouteTable& rtable, Dev& forward_que, std::ostream& log):
+    ip(ip), rtable(rtable), forward_que(forward_que), log(log)
 {
 }
 
@@ -24,6 +29,17 @@ bool IPOut::send(const std::string& data, uint8_t proto, IPAddr dst, IPAddr src,
         bool df, uint8_t ttl, uint16_t id)
     throw (std::runtime_error)
 {
+    // Mando todo lo que tengo para forwardear
+    while (to_forward())
+    {
+        std::string buf = forward_que.receive();
+        IPHeader iph(buf);
+#ifdef DEBUG
+        log << "IPOut::send: A forwardear => IPHeader: " << iph << "\n";
+#endif
+        send(iph, buf.substr(iph.header_len()));
+    }
+    // Mando el paquete en sí
     // Armamos cabecera
     if (!src)
         src = ip;
@@ -31,15 +47,21 @@ bool IPOut::send(const std::string& data, uint8_t proto, IPAddr dst, IPAddr src,
         id = get_id();
     IPHeader iph(4, IPHeader::header_len() + data.size(), id, df, 0, 0,
             ttl, proto, src, dst);
+    return send(iph, data);
+}
+
+/// Envía un paquete IP
+bool IPOut::send(IPHeader iph, std::string data) throw (std::runtime_error)
+{
     // Buscamos ruta
-    RouteTable::Route* r = rtable.get(dst);
+    RouteTable::Route* r = rtable.get(iph.dst);
     if (!r)
     {
         drop("No existe una ruta para el destino", iph);
         return false;
     }
     // No quieren fragmentar
-    if (df && (IPHeader::header_len() + data.size() > r->iface->mtu))
+    if (iph.df && (IPHeader::header_len() + data.size() > r->iface->mtu))
     {
         drop("Tamaño de paquete más grande que MTU y DF=1", iph);
         return false;
@@ -63,7 +85,7 @@ bool IPOut::send(const std::string& data, uint8_t proto, IPAddr dst, IPAddr src,
         log << "IPOut::send: Fragmento 0 => IPHeader: " << iph2 << "\n";
         log << "\tbuf (" << buf.size() << ") = " << buf << "\n";
 #endif
-        r->iface->transmit(buf, r->gateway ? r->gateway : dst);
+        r->iface->transmit(buf, r->gateway ? r->gateway : IPAddr(iph.dst));
     }
     return true;
 }
@@ -74,4 +96,12 @@ uint16_t IPOut::get_id() const
     return time(NULL);
 }
 
+/// Se fija si hay paquetes a forwardear (y devuelve cuantos hay)
+unsigned IPOut::to_forward()
+{
+    struct msqid_ds minfo;
+    msgctl(forward_que.que_id, IPC_STAT, &minfo);
+    return minfo.msg_qnum;
+}
+
 // vim: set et sw=4 sts=4 :