[controller] insert 6->4 session

doc/plan.org

@@ -1432,7 +1432,6 @@ Please make sure that it is installed and available in your $PATH:
        steps
      - Longer than /96: suffix support
 
-
 ** Motivation
    TBD
 ** Translation mechanisms
@@ -1856,10 +1855,23 @@ libnanomsg-dev libjudy-dev
 ***** TODO Case IPv4 initiator
       - Needs upper level protol
 **** TODO General network matching
-***** TODO Create table
+***** DONE Create table(s)
-***** TODO Fill it up from the controller
+***** DONE Fill it up from the controller: general network
-**** TODO tcp session
+***** TODO Create controller session handler
+****** Controller Logic
+       - controller selects "outgoing" IPv4 address range => base for sessions
+       - IPv4 addresses can be "random" (in our test case), but need
+         to be unique
+       - switch does not need to know about the "range", only about
+         sessions
+       - on session create, controller selects "random" ip (ring?)
+       - on session create, controller selects "random port" (next in range?)
+       - on session create controller adds choice into 2 tables:
+         incoming, outgoing
 
+***** DONE Feed back to controller: implemented in switch
+***** TODO Create session in the controller
+**** TODO tcp session
 **** TODO udp session
 **** TODO tcp session
 ** TODO Comparison with existing tools (Performance, Features)

p4app/controller.py

@@ -26,7 +26,8 @@ cpu_fields = {
     0: 'UNSET',
     1: 'ICMP6_NS',
     2: 'ICMP6_GENERAL',
-    3: 'DEBUG'
+    3: 'DEBUG',
+    8: 'NAT64_TCP_SESSION'
 }
 
 table_id_fields = {
@@ -73,7 +74,7 @@ class CpuHeader(Packet):
 class L2Controller(object):
     def __init__(self, sw_name):
         # Command line mapping
-        self.modes = ['base', 'router', "range_router" ]
+        self.modes = ['base', 'router', "range_router", "session_router" ]
 
         # Reverse maps the cpu header
         self.task = dict(reversed(item) for item in cpu_fields.items())
@@ -112,11 +113,13 @@ class L2Controller(object):
 
         # /96 after the /40 pool we use above
         self.info['nat64_prefix_dynamic'] = ipaddress.ip_network("2001:db8:100::/96")
+        self.info['nat64_tcp_session'] = {}
 
         self.v6_routes = {}
         self.v6_routes[None] = []
         self.v6_routes['base'] = []
 
+
         self.ports = []
 
         for port in range(1,3):
@@ -130,8 +133,10 @@ class L2Controller(object):
 
         self.v6_routes['router'] = self.v6_routes['base']
 
+
         # only 1 route to avoid table duplicate/conflict
         self.v6_routes['range_router'] = self.v6_routes['base'][0:1]
+        self.v6_routes['session_router'] = self.v6_routes['range_router']
 
         self.v4_routes = {}
         self.v4_routes[None] = []
@@ -147,6 +152,7 @@ class L2Controller(object):
 
         self.v4_routes['router'] = self.v4_routes['base']
         self.v4_routes['range_router'] = self.v4_routes['base']
+        self.v4_routes['session_router'] = self.v4_routes['base']
 
         self.v6_addresses = {}
         self.v6_addresses[None] = []
@@ -159,9 +165,12 @@ class L2Controller(object):
             self.v4_addresses[mode] = [ net['net'][self.info['switch_suffix']] for net in self.v4_routes[mode] ]
 
         self.nat64_map = {}
+        self.nat64_session_net = {}
+
         # init default
         for mode in self.modes:
             self.nat64_map[mode] = []
+            self.nat64_session_net[mode] = []
 
         # specific settings - mapping 256 IPv6 IPs max statically (based on /24)
         for mode in ["range_router"]:
@@ -183,6 +192,16 @@ class L2Controller(object):
                     "v4_dst": v4_dst
                 })
 
+        # allow session translation
+        # TODO: maybe support multiple networks
+        for mode in ["session_router"]:
+            self.nat64_session_net[mode] = [
+                { 'v4_net': self.info['v4_nat64_map'].next(),
+                  'v6_net': self.info['nat64_prefix_dynamic'],
+                  'v4_idx': 1
+                }
+            ]
+
         self.init_boilerplate(sw_name)
         self.init_other_port_multicast_groups()
 
@@ -313,6 +332,23 @@ class L2Controller(object):
         for nat64map in self.nat64_map[self.mode]:
             self.static_nat64_mapping(**nat64map)
 
+        # NAT64 session based
+        self.controller.table_clear("nat64_session")
+
+        # These will be only populated dynamically
+        self.controller.table_clear("nat64_tcp_session")
+        self.controller.table_clear("nat46_tcp_session")
+
+        for net in self.nat64_session_net[mode]:
+            # Only for matching / if selecting
+            self.controller.table_add("nat64_session", "NoAction",
+                                      [
+                                          net['v6_net']
+                                      ]
+            )
+
+
+
     def static_nat64_mapping(self, v6_src, v6_dst, v4_src, v4_dst):
         """
         Currently using destination only matching due to non priority
@@ -475,6 +511,67 @@ class L2Controller(object):
 
         self.send_pkg(answer)
 
+    def nat64_tcp_session_entry(self, ipv6_src_addr, ipv6_dst_addr,
+                                tcp_src_port, tcp_dst_port):
+
+        return "{}:{} - {}:{}".format(ipv6_src_addr, tcp_src_port,
+                                      ipv6_dst_addr, tcp_dst_port)
+
+
+    def nat64_create_tcp_session(self, pkg):
+        """
+        session:
+            hdr.ipv6.src_addr: exact;
+            hdr.ipv6.dst_addr: exact;
+            hdr.tcp.src_port:  exact;
+            hdr.tcp.dst_port:  exact;
+        """
+
+
+        id = self.nat64_tcp_session_entry(pkg[IPv6].src,
+                                          pkg[TCP].src_port,
+                                          pkg[IPv6].dst,
+                                          pkg[TCP].dst_port)
+
+
+        # Has already been added? then it's a race condition and
+        # it needs to go back to the switch
+
+
+        # Not in the table? create an entry!
+        if not id in self.info['nat64_tcp_session']:
+
+            # FIXME: Change randomly later, supporting 1:N mappings
+            # Keep the same for the moment
+            tcp_src_port = pkg[TCP].src_port
+            tcp_dst_port = pkg[TCP].dst_port
+
+            # FIXME: range, reuse, etc.
+            ipv4_src_addr = self.nat64_session_net[self.mode]
+            self.nat64_session_net[self.mode] += 1
+
+
+            self.controller.table_add("nat64_tcp_session",
+                                      "nat64_tcp_session_translate",
+                                      [
+                                          pkg[IPv6].src,
+                                          pkg[TCP].src_port,
+                                          pkg[IPv6].dst,
+                                          pkg[TCP].dst_port
+                                      ],
+                                      [
+                                          ipv4_src_addr,
+                                          tcp_src_port,
+                                          ipv4_dst_addr,
+                                          tcp_dst_port
+                                      ]
+            )
+
+
+        self.send_pkg(pkg)
+
+
+
     def send_pkg(self, pkg):
         self.debug_print_pkg(pkg, "OUTGOING")
         sendp(pkg, iface=self.intf, verbose=False)
@@ -494,6 +591,7 @@ class L2Controller(object):
 
             ether_orig = Ether(src=packet.src, dst=packet.dst, type=cpu_header.type)
 
+            # Note to myself: this is actually broken for ARP
             if cpu_header.type == 0x0800:
                 orig_packet = ether_orig / IP(cpu_header.load)
             elif cpu_header.type == 0x86dd:
@@ -520,6 +618,8 @@ class L2Controller(object):
         elif cpu_header.task == self.task['ICMP6_GENERAL']:
             if ICMPv6EchoRequest in orig_packet:
                 self.handle_icmp6_echo_request(orig_packet)
+        elif cpu_header.task == self.task['NAT64_TCP_SESSION']:
+            self.nat64_create_tcp_session(orig_packet)
         else:
             log.info("unhandled reassambled={} from table {}".format(orig_packet.__repr__(), table_id_fields[cpu_header.table_id]))
 

p4src/nat64.p4

@@ -298,7 +298,6 @@ Echo or Echo Reply Message
             NoAction;
         }
         size = NAT64_TABLE_SIZE;
-        //default_action = controller_debug_table_id(TABLE_NAT64_TCP);
         default_action = nat64_tcp_session_create;
     }