Add uebung1 pdf

uebung1_example_original.py

@@ -10,12 +10,11 @@ from ryu.lib.packet import ipv4
 from ryu.lib.packet import icmp
 from ryu.lib.packet.arp import arp
 from ryu.lib.packet.packet import Packet
-#from ryu.ofproto.ofproto_v1_3 import OFPActionSetField
 
 class L3Switch(app_manager.RyuApp):
     OFP_VERSIONS = [ofproto_v1_3.OFP_VERSION]
 
-    IP_ADDR = ["10.0.0.254", "10.0.1.254", "10.0.2.254"]
+    IP_ADDR = "10.0.0.254"
     MAC_ADDR = "52:00:00:00:00:01"
 
     def __init__(self, *args, **kwargs):
@@ -91,11 +90,11 @@ class L3Switch(app_manager.RyuApp):
             # arp request
             arp_dstIp = arpPacket.dst_ip
             self.logger.info('received ARP Request %s => %s (port%d)'%(frame.src, frame.dst, inPort))
-            if arp_dstIp in self.IP_ADDR:
+            if arp_dstIp == self.IP_ADDR:
                 # this switch was requested
                 opcode = 2
                 srcMAC  = self.MAC_ADDR
-                srcIP   = arp_dstIp
+                srcIP   = self.IP_ADDR
                 dstMAC  = frame.src
                 dstIP   = arpPacket.src_ip
                 outPort = inPort
@@ -128,14 +127,6 @@ class L3Switch(app_manager.RyuApp):
                     self.ip_to_mac[dpid][srcIP] = srcMAC
                     self.logger.info("froward ARP request %s => %s (port%d)" %(srcMAC, dstMAC, outPort))
         elif arpPacket.opcode == 2 :
-            self.logger.info(arpPacket)
-            if  arpPacket.dst_mac == self.MAC_ADDR:
-                # learn mac 2 port mapping
-                self.mac_to_port[dpid][arpPacket.src_mac] = inPort
-                # learn ip 2 mac mapping
-                self.ip_to_mac[dpid][arpPacket.src_ip] = arpPacket.src_mac
-                return
-            else:
             opcode = 2
             #arp reply
             # forward arp reply
@@ -167,8 +158,6 @@ class L3Switch(app_manager.RyuApp):
         self.send_packet(datapath, outPort, p)
 
     def do_icmp(self, datapath, port, pkt_ethernet, pkt_ipv4, pkt_icmp):
-        self.logger.info(pkt_icmp.type)
-        self.logger.info(icmp.ICMP_ECHO_REQUEST)
         if pkt_icmp.type != icmp.ICMP_ECHO_REQUEST:
             return
         pkt = packet.Packet()
@@ -176,14 +165,13 @@ class L3Switch(app_manager.RyuApp):
                                            dst=pkt_ethernet.src,
                                            src=self.MAC_ADDR))
         pkt.add_protocol(ipv4.ipv4(dst=pkt_ipv4.src,
-                                   src=pkt_ipv4.dst,
+                                   src=self.IP_ADDR,
                                    proto=pkt_ipv4.proto))
         pkt.add_protocol(icmp.icmp(type_=icmp.ICMP_ECHO_REPLY,
                                    code=icmp.ICMP_ECHO_REPLY_CODE,
                                    csum=0,
                                    data=pkt_icmp.data))
         self.logger.info("do icmp: %s" %(pkt,))
-        self.logger.info("port: %s" %(port))
         self.send_packet(datapath, port, pkt)
 
     def do_l2_switch(self, datapath, dpid, packet, frame, in_port, buffer_id=None):
@@ -215,52 +203,6 @@ class L3Switch(app_manager.RyuApp):
                                   in_port=in_port, actions=actions, data=data)
         datapath.send_msg(out)
 
-    def do_l3_switch(self, datapath, dpid, packet, frame, ipv4_pkt, in_port, buffer_id=None):
-        ofproto = datapath.ofproto
-        parser = datapath.ofproto_parser
-
-        if ipv4_pkt.dst in self.ip_to_mac[dpid]:
-            # GEt mac and port of the given destination
-            dstMac = self.ip_to_mac[dpid][ipv4_pkt.dst]
-            out_port = self.mac_to_port[dpid][dstMac]
-        else:
-            # Send an arp request and define mac and port
-            # so we're able to apply the following actions
-            # on the packet.
-            out_port = ofproto.OFPP_FLOOD
-            dstMac = "FF:FF:FF:FF:FF:FF"
-            self.send_arp(datapath, 1, self.MAC_ADDR, ipv4_pkt.src, dstMac, ipv4_pkt.dst, out_port)
-
-        # Actions are applied in the same order as defined in the list.
-        # OFPActionOutput terminates the chain. So this call should be the last action.
-        actions = [parser.OFPActionDecNwTtl(), #decrease TTL count
-            parser.OFPActionSetField(eth_src=self.MAC_ADDR), # set own mac as source
-            parser.OFPActionSetField(eth_dst=dstMac), # set dst from arp request
-            parser.OFPActionOutput(out_port)] # forward packet through out_port
-
-        # Only install a flow if we#re in the first case (specific mac and out_port)
-        if ipv4_pkt.dst in self.ip_to_mac[dpid]:
-            # install a flow to avoid packet_in next time
-            match = parser.OFPMatch(in_port=in_port, ipv4_dst=ipv4_pkt.dst, eth_type=0x0800) #onlz match ipv4 packets
-
-            # 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
-
-        out = parser.OFPPacketOut(datapath=datapath, buffer_id=buffer_id,
-                                  in_port=in_port, actions=actions, data=data)
-        datapath.send_msg(out)
-
-
-
     @set_ev_cls(ofp_event.EventOFPPacketIn, MAIN_DISPATCHER)
     def _packet_in_handler(self, ev):
         # If you hit this you might want to increase
@@ -289,7 +231,6 @@ class L3Switch(app_manager.RyuApp):
         self.mac_to_port.setdefault(dpid, {})
         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)
 
         #learn mac to port mapping
@@ -304,14 +245,13 @@ class L3Switch(app_manager.RyuApp):
             ipv4_pkt = pkt.get_protocol(ipv4.ipv4)
 
             #check if packet is for this switch
-            if ipv4_pkt.dst in self.IP_ADDR:
+            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)
             else:
-                # forward the package into a different subnet
+                # here we would forward the packet into other subnets
-                self.do_l3_switch(datapath, dpid, pkt, eth, ipv4_pkt, in_port, msg.buffer_id)
+                pass
-
 
         # packet is not for this switch, so do l2 switching
         if dst != self.MAC_ADDR: