Add icmp handling / replying

doc/plan.org

@@ -173,6 +173,10 @@
 | 2019-04-02 |                                                                            |       |
 |            | ARP egress support                                                         |       |
 |            |                                                                            |       |
+| 2019-04-03 |                                                                            |       |
+|            | ARP corrections -- ARP working for the switch!                             |       |
+|            |                                                                            |       |
+|            |                                                                            |       |
 | 2019-04-04 | NAT64 1:1 table ICMP, ICMPv6 working                                       |       |
 |            | Will need some switch local ip addresses                                   |       |
 |            |                                                                            |       |
@@ -681,16 +685,17 @@ INFO:main:unhandled reassambled=<Ether  dst=00:00:0a:00:00:42 src=00:00:0a:00:00
 ***** DONE egress is correct, comes out at h3
 ***** DONE protocol 58 is wrong -> should be 1
 ***** DONE figure out switch() syntax
-***** TODO transform protocol specific: icmp6 -> icmp
+***** DONE transform protocol specific: icmp6 -> icmp
 ****** DONE Implement double table, as there are no if's in actions
 ****** DONE Debug Ethernet frame check sequence error -> need to compute checksum
        https://en.wikipedia.org/wiki/Frame_check_sequence
 
 According to Edgar this should not be seen anyway.
-****** TODO Calculate ICMP checksum
+****** DONE Calculate ICMP checksum
-****** TODO Check field lengths
+****** DONE Check field lengths
 ***** TODO transform protocol specific: icmp -> icmp6
-**** TODO Make switch answer IPv4 icmp echo request for
+****** TODO Make switch answer IPv4 icmp echo request for
+******* DONE Make switch respond to ARP
 **** TODO Add / check default route for v4 hosts
 **** TODO Update p4c to avoid compiler bug
 ***** TODO Updating p4c

p4app/controller.py

@@ -37,7 +37,8 @@ table_id_fields = {
     4: 'TABLE_NAT46',
     5: 'TABLE_V4_NETWORKS',
     6: 'TABLE_ARP',
-    7: 'TABLE_ARP_EGRESS'
+    7: 'TABLE_ARP_EGRESS',
+    8: 'TABLE_ICMP'
 }
 
 table_proto = {
@@ -224,7 +225,7 @@ class L2Controller(object):
     def init_ndp_in_switch(self, addr):
         icmp6_addr = self.gen_ndp_multicast_addr(addr)
         icmp6_net = "{}/128".format(icmp6_addr)
-        icmp6_type = 135
+        icmp6_type = table_proto['ICMP_NS']
         mac_addr =  self.info['mac_addr']
 
         self.controller.table_add("icmp6",
@@ -233,13 +234,21 @@ class L2Controller(object):
 
     def init_icmp6_echo_in_switch(self, addr):
         icmp6_addr = addr
-        icmp6_type = 128
+        icmp6_type = table_proto['ICMP6_ECHO_REQUEST']
         icmp6_net = "{}/128".format(icmp6_addr)
 
         self.controller.table_add("icmp6",
                                   "icmp6_echo_reply",
                                   [str(icmp6_net), str(icmp6_type)], [])
 
+    def init_icmp_echo_in_switch(self, addr):
+        icmp_addr = addr
+        icmp_type = table_proto['ICMP_ECHO_REQUEST']
+        icmp_net = "{}/32".format(icmp_addr)
+
+        self.controller.table_add("icmp",
+                                  "icmp_echo_reply",
+                                  [str(icmp_net), str(icmp_type)], [])
 
     def ipv4_router(self, net):
         return net[self.info['switch_suffix']]
@@ -251,6 +260,7 @@ class L2Controller(object):
 
         self.controller.table_clear("v4_networks")
         self.controller.table_clear("v4_arp")
+        self.controller.table_clear("v4_arp_egress")
         for v4route in self.v4_routes[self.mode]:
             self.controller.table_add("v4_networks", "set_egress_port", [str(v4route['net'])], [str(v4route['port'])])
 
@@ -267,11 +277,17 @@ class L2Controller(object):
         if self.args.multicast_to_controller:
             self.listen_to_icmp6_multicast()
 
+        # icmp6 echo request + NDP
         self.controller.table_clear("icmp6")
         for v6addr in self.v6_addresses[self.mode]:
             self.init_ndp_in_switch(v6addr)
             self.init_icmp6_echo_in_switch(v6addr)
 
+        # icmp echo request
+        self.controller.table_clear("icmp")
+        for addr in self.v4_addresses[self.mode]:
+            self.init_icmp_echo_in_switch(addr)
+
         self.controller.table_clear("nat64")
         self.controller.table_clear("nat46")
         for nat64map in self.nat64_map[self.mode]:

p4src/headers.p4

@@ -24,6 +24,7 @@ const bit<16> TABLE_NAT46       = 4;
 const bit<16> TABLE_V4_NETWORKS = 5;
 const bit<16> TABLE_ARP         = 6;
 const bit<16> TABLE_ARP_EGRESS  = 7;
+const bit<16> TABLE_ICMP        = 8;
 
 
 const bit<16> TYPE_IPV4  = 0x0800;

p4src/settings.p4

@@ -11,6 +11,7 @@
 #define ADDRESS_TABLE_SIZE 64                               /* maximum number of addresses per protocol */
 #define NDP_TABLE_SIZE 64                                   /* maximum number of multicast groups */
 #define ICMP6_TABLE_SIZE 64                                 /* icmp6 handlers */
+#define ICMP_TABLE_SIZE 64                                 /* icmp6 handlers */
 #define NAT64_TABLE_SIZE 64                                 /* nat64 and nat46 entries */
 
 #endif

p4src/static-mapping.p4

@@ -225,9 +225,9 @@ Echo or Echo Reply Message
     }
 
 
-    /********************** ICMP6 + NDP ***********************************/
+    /********************** ICMP6 + NDP + ICMP ***********************************/
 
-    /* old/unused action */
+    /* old/unused action -- is it??*/
     action icmp6_answer() {
         if(hdr.icmp6.isValid()) {
             if(hdr.icmp6.code == ICMP6_ECHO_REQUEST) {
@@ -299,7 +299,28 @@ Echo or Echo Reply Message
         }
         size = ICMP6_TABLE_SIZE;
         default_action = controller_debug_table_id(TABLE_ICMP6);
-//        default_action = NoAction;
+    }
+
+    action icmp_echo_reply() {
+        ipv4_addr_t tmp = hdr.ipv4.src_addr;
+
+        hdr.icmp.type = ICMP_ECHO_REPLY;
+        hdr.ipv4.src_addr = hdr.ipv4.dst_addr;
+        hdr.ipv4.dst_addr = tmp;
+    }
+
+    table icmp {
+        key = {
+            hdr.ipv4.dst_addr: lpm;
+            hdr.icmp.type: exact;
+        }
+        actions = {
+            icmp_echo_reply;
+            controller_debug_table_id;
+            NoAction;
+        }
+        size = ICMP_TABLE_SIZE;
+        default_action = controller_debug_table_id(TABLE_ICMP);
     }
 
     /********************** debugging / general support ***********************************/
@@ -440,7 +461,10 @@ Echo or Echo Reply Message
 
             v6_networks.apply(); /* regular egress / routing */
         } else if(hdr.ipv4.isValid()) {
-            if(nat46.apply().hit) {
+            if(icmp.apply().hit()) {
+                v4_networks.apply();
+                exit;
+            } else if(nat46.apply().hit) {
                 if(hdr.icmp.isValid()) {
                     nat46_icmp_generic();