Add comments and cleanup

Uebung1/controller_1_2.py

@@ -1,3 +1,6 @@
+# Abgabe von:
+# Jutta Seth, Janek Schoffit, Eva Högner
+# Problem 1.2 (Simple IP routing)
 from ryu.base import app_manager
 from ryu.controller import ofp_event
 from ryu.controller.handler import CONFIG_DISPATCHER, MAIN_DISPATCHER

Uebung1/controller_1_3_1.py

@@ -1,3 +1,6 @@
+# Abgabe von:
+# Jutta Seth, Janek Schoffit, Eva Högner
+# Problem 1.3 (IP Router for IPv4)
 from ryu.base import app_manager
 from ryu.controller import ofp_event
 from ryu.controller.handler import CONFIG_DISPATCHER, MAIN_DISPATCHER

Uebung1/controller_1_4.py

@@ -1,3 +1,6 @@
+# Abgabe von:
+# Jutta Seth, Janek Schoffit, Eva Högner
+# Problem 1.4 (Packet-based IP Anycast)
 from ryu.base import app_manager
 from ryu.controller import ofp_event
 from ryu.controller.handler import CONFIG_DISPATCHER, MAIN_DISPATCHER
@@ -23,8 +26,10 @@ class L3Switch(app_manager.RyuApp):
         self.mac_to_port = {}
         self.port_to_mac = {}
         self.ip_to_mac = {}
+
+        # Define the ports for anycast round robin
         self.anycastPorts = [1, 3, 4]
-        self.anycastIndex = 0
+        self.anycastIndex = 0 # round robin index for the ports array
 
     @set_ev_cls(ofp_event.EventOFPSwitchFeatures, CONFIG_DISPATCHER)
     def switch_features_handler(self, ev):
@@ -190,18 +195,10 @@ class L3Switch(app_manager.RyuApp):
         else:
             out_port = ofproto.OFPP_FLOOD
 
-        actions = [parser.OFPActionOutput(out_port)]
+        # add_flow removed, otherwise the controller wouldn't receive new packets
+        # for the anycast switching.
 
-        # install a flow to avoid packet_in next time
+        actions = [parser.OFPActionOutput(out_port)]
-        if out_port != ofproto.OFPP_FLOOD:
-            match = parser.OFPMatch(in_port=in_port, eth_dst=frame.dst)
-            # verify if we have a valid buffer_id, if yes avoid to send both
-            # flow_mod & packet_out
-            #if buffer_id != ofproto.OFP_NO_BUFFER:
-            #    self.add_flow(datapath, 1, match, actions, buffer_id)
-            #    return
-            #else:
-            #    self.add_flow(datapath, 1, match, actions)
         data = None
         if buffer_id == ofproto.OFP_NO_BUFFER:
             data = packet.data
@@ -210,6 +207,7 @@ class L3Switch(app_manager.RyuApp):
                                   in_port=in_port, actions=actions, data=data)
         datapath.send_msg(out)
 
+    # Get the next port where a package should be forwarded
     def anycast_next(self):
         if self.anycastIndex >= 2:
             self.anycastIndex = 0
@@ -221,8 +219,10 @@ class L3Switch(app_manager.RyuApp):
         ofproto = datapath.ofproto
         parser = datapath.ofproto_parser
 
+        # Select a port
         port = self.anycast_next()
 
+        # Send the package without adding a flow
         packet.get_protocols(ethernet.ethernet)[0].dst = self.port_to_mac[dpid][str(port)]
         self.send_packet(datapath, port, packet)
 
@@ -273,6 +273,7 @@ class L3Switch(app_manager.RyuApp):
                 icmp_pkt = pkt.get_protocol(icmp.icmp)
                 if icmp_pkt:
                     self.do_icmp(datapath, in_port, eth, ipv4_pkt, icmp_pkt)
+            # Do anycast if the package contains the anycast dst-IP
             if ipv4_pkt.dst == "10.0.0.100":
                 self.do_anycast(datapath, dpid, pkt, eth, in_port, msg.buffer_id)
                 return

Uebung1/controller_1_4_2.py

@@ -1,3 +1,6 @@
+# Abgabe von:
+# Jutta Seth, Janek Schoffit, Eva Högner
+# Problem 1.4 (Flow-based IP Anycast)
 from ryu.base import app_manager
 from ryu.controller import ofp_event
 from ryu.controller.handler import CONFIG_DISPATCHER, MAIN_DISPATCHER
@@ -210,6 +213,7 @@ class L3Switch(app_manager.RyuApp):
                                   in_port=in_port, actions=actions, data=data)
         datapath.send_msg(out)
 
+    # Get the next port where a package should be forwarded
     def anycast_next(self):
         if self.anycastIndex >= 2:
             self.anycastIndex = 0
@@ -222,18 +226,18 @@ class L3Switch(app_manager.RyuApp):
         ofproto = datapath.ofproto
         parser = datapath.ofproto_parser
 
+        # Retrieve tcp tuple
         tcp_pkt = packet.get_protocol(tcp.tcp)
         tcp_src = tcp_pkt.src_port
         tcp_dst = tcp_pkt.dst_port
 
-        self.logger.info("src: %s, dst: %s", tcp_src, tcp_dst)
+        # Get the anycast port
         port = self.anycast_next()
 
         actions = [parser.OFPActionSetField(eth_dst = self.port_to_mac[dpid][str(port)]),
                     parser.OFPActionOutput(port)]
 
         match = parser.OFPMatch(eth_type=0x0800, ipv4_src=ipv4_pkt.src, ip_proto=6, tcp_src=tcp_src, ipv4_dst=ipv4_pkt.dst, tcp_dst=tcp_dst)
-        #match = parser.OFPMatch(in_port=in_port, eth_dst=frame.dst, tcp_src=tcp_src)
 
         if buffer_id != ofproto.OFP_NO_BUFFER:
             self.add_flow(datapath, 1, match, actions, buffer_id)
@@ -280,7 +284,6 @@ class L3Switch(app_manager.RyuApp):
         self.ip_to_mac.setdefault(dpid, {})
 
         self.logger.info("packet in dpid: %s, src: %s, dest: %s, in_port: %s", dpid, src, dst, in_port)
-        #self.logger.info(pkt)
 
         #learn mac to port mapping
         if src not in self.mac_to_port[dpid]:
@@ -291,13 +294,13 @@ class L3Switch(app_manager.RyuApp):
             return
 
         if eth.ethertype == ether_types.ETH_TYPE_IP:
-
             ipv4_pkt = pkt.get_protocol(ipv4.ipv4)
             #check if packet is for this switch
             if ipv4_pkt.dst == self.IP_ADDR:
                 icmp_pkt = pkt.get_protocol(icmp.icmp)
                 if icmp_pkt:
                     self.do_icmp(datapath, in_port, eth, ipv4_pkt, icmp_pkt)
+            # Do anycast if the package contains the anycast dst-IP
             if ipv4_pkt.dst == "10.0.0.100":
                 self.do_anycast(datapath, dpid, pkt, eth, in_port, ipv4_pkt, msg.buffer_id)
                 return