Transport table debug information to controller

doc/plan.org

@@ -422,7 +422,24 @@ Problem: task field might be overriden for controller use in different
 table -> need different task field!
 
 ***** try2: checksum ok, but no packets on h3
-****** Setup a default rule for the IPv4 world to debug on controller
+****** DONE Setup a default rule for the IPv4 world to debug on controller
+Still not seeing the converted packet, however seeing icmp6_ns packets
+which should not be there:
+
+table entry for ns:
+
+ff:02:00:00:00:00:00:00:00:00:00:01:ff:00:00:42/128
+
+debug packet seen in controller:
+
+DEBUG:main:v6 reassambled=<Ether  dst=33:33:ff:00:00:42 src=00:00:0a:00:00:01 type=0x86dd |<IPv6  version=6 tc=0 fl=0 plen=32 nh=ICMPv6 hlim=255 src=fe80::200:aff:fe00:1 dst=ff02::1:ff00:42 |<ICMPv6ND_NS  type=Neighbor Solicitation code=0 cksum=0x37df res=0 tgt=2001:db8::42 |<ICMPv6NDOptSrcLLAddr  type=1 len=1 lladdr=00:00:0a:00:00:01 |>>>>
+DEBUG:main:v6 reassambled=<Ether  dst=33:33:ff:00:00:42 src=00:00:0a:00:00:01 type=0x86dd |<IPv6  version=6 tc=0 fl=0 plen=32 nh=ICMPv6 hlim=255 src=fe80::200:aff:fe00:1 dst=ff02::1:ff00:42 |<ICMPv6ND_NS  type=Neighbor Solicitation code=0 cksum=0x37df res=0 tgt=2001:db8::42 |<ICMPv6NDOptSrcLLAddr  type=1 len=1 lladdr=00:00:0a:00:00:01 |>>>>
+DEBUG:main:v6 reassambled=<Ether  dst=33:33:ff:00:00:42 src=00:00:0a:00:00:01 type=0x86dd |<IPv6  version=6 tc=0 fl=0 plen=32 nh=ICMPv6 hlim=255 src=2001:db8::1 dst=ff02::1:ff00:42 |<ICMPv6ND_NS  type=Neighbor Solicitation code=0 cksum=0x13a7 res=0 tgt=2001:db8::42 |<ICMPv6NDOptSrcLLAddr  type=1 len=1 lladdr=00:00:0a:00:00:01 |>>>>
+
+DEBUG:main:v6 reassambled=<Ether  dst=00:00:0a:00:00:42 src=00:00:0a:00:00:01 type=0x86dd |<IPv6  version=6 tc=0 fl=920946 plen=64 nh=ICMPv6 hlim=64 src=2001:db8::1 dst=2001:db8:1::a00:1 |<ICMPv6EchoRequest  type=Echo Request code=0 cksum=0xf981 id=0x5f7c seq=0x1 data='N\xc6\x98\\\x00\x00\x00\x00\x12\x1b\t\x00\x00\x00\x00\x00\x10\x11\x12\x13\x14\x15\x16\x17\x18\x19\x1a\x1b\x1c\x1d\x1e\x1f !"#$%&\'()*+,-./01234567' |>>>
+
+debugging MIGHT come from nat64 table!
+
 
 *** TODO Get p4 VM / vagrant running
 **** DONE install libvirtd-daemon
@@ -1219,8 +1236,8 @@ debug packets - analyse code - goto 1
  [21:26] line:~% sudo apt install thrift-compiler
  libnanomsg-dev libjudy-dev
 *** Performance comparison
-*** Feature/Functionality difference / overview / CHALLENGES / LIMITATIONS in P4
+*** Challenges / Limitations in P4
-**** P4: cannot read key from table
+**** DONE cannot read key from table
 ***** log
 Key and mask for matching destination is in table. We need this
  information in the action. However this information is not exposed, so
@@ -1285,7 +1302,7 @@ Need to duplicate information
 **** DONE ICMP6: checksum over payload
      - variable length, up to 65k
 Exists!
-**** Synchronisation with the controller
+**** DONE Synchronisation with the controller
      - Double data type definition -> might differ
      - TYPE_CPU for ethernet
      - Port ingress offset (9 vs. 16 bit)
@@ -1315,18 +1332,29 @@ Code:
     }
 #+END_SRC
 
-**** (current) Implementation limitations
+**** No table meta information for default actions (asked 2019-03-25)
-***** No fragmentation support (yet)
+Is there any meta information for "from which table was the action
-***** No session handling (yet)
+called" available? My use case is having a debug action that sends
+packets to the controller and I use it as a default_action in various
+tables; however know I don't know anymore from which table the action
+was called. Is there any kind of meta information which table called
+me available?
+
+I could work around this by using if(! .. .hit) { my_action(table_id)
+}, but it would not work with using default_action = ...
+
+*** Implementation limitations
+**** No fragmentation support (yet)
+**** No session handling (yet)
 1:1 mappings. No (automatic) session.
-***** IPv4 / IPv6 embedding
+**** IPv4 / IPv6 embedding
 Currently offset based - probably not following the RFC!
-***** No DNS64
+**** No DNS64
 has already been solved in a different domain - could even do
 transparent / in network modification
-***** Incomplete NDP
+**** Incomplete NDP
-      Very limited option support
+     Very limited option support
-***** NAT64 mappings not source network dependent
+**** NAT64 mappings not source network dependent
 Only the destination network is matched for deciding on NAT64, as
 priority based double LPM is not supported. This limits a prefix to be
 used only in one network.

p4app/controller.py

@@ -23,11 +23,20 @@ log = logging.getLogger("main")
 
 
 cpu_fields = {
+    0: 'UNSET',
     1: 'ICMP6_NS',
     2: 'ICMP6_GENERAL',
     3: 'DEBUG'
 }
 
+table_id_fields = {
+    0: 'UNSET_TABLE',
+    1: 'TABLE_NAT64',
+    2: 'TABLE_ICMP6,
+    3: 'TABLE_V6_NETWORKS,
+    4: 'TABLE_NAT46',
+    5: 'TABLE_V4_NETWORKS'
+}
 
 class CpuHeader(Packet):
     name = 'CpuPacket'
@@ -35,6 +44,7 @@ class CpuHeader(Packet):
         ShortEnumField('task', 1, cpu_fields ),
         ShortField('ingress_port', 0),
         XShortEnumField("type", 0x9000, ETHER_TYPES)
+        ShortEnumField('table_id', 1, table_id_fields ),
     ]
 
 
@@ -421,8 +431,6 @@ class L2Controller(object):
     def recv_msg_cpu(self, pkg):
         packet = Ether(str(pkg))
 
-
-
         if packet.type == 0x0800:
             log.debug("Received raw (untagged) packet - BUG")
             self.debug_print_pkg(pkg)
@@ -432,13 +440,14 @@ class L2Controller(object):
             cpu_header = CpuHeader(packet.payload)
             ether_orig = Ether(src=packet.src, dst=packet.dst, type=cpu_header.type)
             orig_packet = ether_orig / IP(cpu_header.load)
+            log.debug("cpu = {}".format(cpu_header.__repr__()))
             log.debug("v4 reassambled={}".format(orig_packet.__repr__()))
 
         elif packet.type == 0x4242:
             cpu_header = CpuHeader(packet.payload)
 
             # Not necessary anymore - cpu decoding works
-#            log.debug("cpu = {}".format(cpu_header.__repr__()))
+            log.debug("cpu = {}".format(cpu_header.__repr__()))
 
             ether_orig = Ether(src=packet.src, dst=packet.dst, type=cpu_header.type)
 
@@ -454,7 +463,7 @@ class L2Controller(object):
                 src = orig_packet['IPv6'].src
                 log.debug("Router solicitation from {} -- should probably handle this?".format(src))
             elif cpu_header.task == self.task['DEBUG']:
-                log.debug("v6 reassambled={}".format(orig_packet.__repr__()))
+                log.debug("[debug] v6 reassambled={}".format(orig_packet.__repr__()))
             elif cpu_header.task == self.task['ICMP6_NS']:
                 log.info("Doing neighbor solicitation for the switch in the controller")
                 self.handle_icmp6_ns(orig_packet)

p4src/headers.p4

@@ -12,6 +12,14 @@ typedef bit<9>   port_t;
 typedef bit<16>  mcast_t;
 typedef bit<16>  task_t;
 
+typedef bit<8>  table_t; /* to map debug messages */
+
+const bit<8> TABLE_NAT64       = 1;
+const bit<8> TABLE_ICMP6       = 2;
+const bit<8> TABLE_V6_NETWORKS = 3;
+const bit<8> TABLE_NAT46       = 4;
+const bit<8> TABLE_V4_NETWORKS = 5;
+
 
 const bit<16> TYPE_IPV4  = 0x0800;
 const bit<16> TYPE_IPV6  = 0x86DD;
@@ -148,6 +156,7 @@ header cpu_t {
     task_t task;
     bit<16> ingress_port;
     bit<16> ethertype;
+    table_t table_id;
 }
 
 struct headers {
@@ -169,6 +178,7 @@ struct metadata {
     task_t switch_task;
     bit<16> tcp_length;
     bit<32> cast_length;
+    table_t table_id;
 }
 
 #endif

p4src/static-mapping.p4

@@ -32,6 +32,11 @@ control MyIngress(inout headers hdr,
         clone3(CloneType.I2E, 100, meta);
     }
 
+    action controller_debug_table_id(table_t table_id) {
+        hdr.cpu.table_id = table_id;
+        controller_reply(TASK_DEBUG);
+    }
+
     action controller_debug() {
         controller_reply(TASK_DEBUG);
     }
@@ -242,7 +247,6 @@ control MyIngress(inout headers hdr,
         }
         size = NDP_TABLE_SIZE;
         default_action = NoAction;
-//        default_action = controller_debug;
     }
 
     /* Handle multicast registration of NDP */
@@ -257,7 +261,6 @@ control MyIngress(inout headers hdr,
         }
         size = NDP_TABLE_SIZE;
         default_action = NoAction;
-//        default_action = controller_debug;
     }
 
     /********************** NDP support for OTHERS (unused ATM) ***********************************/
@@ -273,7 +276,7 @@ control MyIngress(inout headers hdr,
             NoAction;
         }
         size = NDP_TABLE_SIZE;
-        default_action = controller_debug;
+        default_action = NoAction;
     }
 
 
@@ -306,7 +309,7 @@ control MyIngress(inout headers hdr,
             NoAction;
         }
         size = ROUTING_TABLE_SIZE;
-        default_action = controller_debug;
+        default_action = NoAction;
     }
 
     table v4_networks {
@@ -319,19 +322,30 @@ control MyIngress(inout headers hdr,
             NoAction;
         }
         size = ROUTING_TABLE_SIZE;
-        default_action = controller_debug;
+        default_action = NoAction;
     }
 
 	/********************** APPLYING TABLES ***********************************/
     apply {
         if(hdr.ipv6.isValid()) {
-            icmp6.apply();       /* icmp6 echo, icmp6 ndp */
+            if(!icmp6.apply().hit) {      /* icmp6 echo, icmp6 ndp */
-            nat64.apply();       /* v6 -> v4 */
+                controller_debug_table_id(TABLE_ICMP6);
-            v6_networks.apply(); /* routing, egress */
+            }
+
+            if(!nat64.apply().hit) { /* v6 -> v4 */
+                controller_debug_table_id(TABLE_NAT64);
+            }
+            if(!v6_networks.apply().hit) {
+                controller_debug_table_id(TABLE_V6_NETWORKS);
+            }
         }
         if(hdr.ipv4.isValid()) {
-            nat46.apply();       /* v4->v6 */
+            if(!nat46.apply().hit) {       /* v4->v6 */
-            v4_networks.apply(); /* routing, egress */
+                controller_debug_table_id(TABLE_NAT46);
+            }
+            if(!v4_networks.apply().hit) { /* routing, egress */
+                controller_debug_table_id(TABLE_V4_NETWORKS)
+            }
         }
     }
 }
@@ -351,6 +365,7 @@ control MyEgress(inout headers hdr,
             hdr.cpu.ethertype = hdr.ethernet.ethertype;
             hdr.cpu.ingress_port = (bit<16>) meta.ingress_port;
 
+
             hdr.ethernet.ethertype = TYPE_CPU;
         }
 	}