packet handling

embedded/atsams70-tinyrouter/atsams70-tinyrouter/src/node.h

+typedef struct {
+	uint8_t portBufferSizes[4];
+  uint16_t LUT[][4]; // TODO: fix representation
+  uint16_t myAddress;
+} node_t;

embedded/atsams70-tinyrouter/atsams70-tinyrouter/src/packet.h

@@ -21,6 +21,8 @@ typedef struct{
 	uint8_t counter;
 }packet_t;
 
+enum packetType {STANDARD, ACK, STANDARD_FLOOD, ACK_FLOOD, BUFFER_UPDATE};
+
 packet_t packet_new(void);
 
 void packet_clean(packet_t *packet);

embedded/atsams70-tinyrouter/atsams70-tinyrouter/src/packet_handling.c

+#include "packet.h"
+#include "node.h"
+
+int parse_type(packet_t* p) {
+  return p->raw[0];
+}
+
+void update_LUT(node_t* n, uint16_t src, uint8_t hopCount, uint8_t port) {
+  n->LUT[src][port] = n->LUT[src][port] > hopCount ? hopCount : n->LUT[src][port];
+}
+
+void send_packet(packet_t* p, uint8_t port) {
+
+}
+
+void broadcast_packet(packet_t* p, uint8_t exclude) {
+  if (exclude != 0) send_packet(p, 0);
+  if (exclude != 1) send_packet(p, 1);
+  if (exclude != 2) send_packet(p, 2);
+  if (exclude != 3) send_packet(p, 3);
+}
+
+packet_t turn_to_standard_flood(node_t n, packet_t* p) {
+  packet_t newPacket = {.raw = p->raw, .destination = p->destination, .source = n->myAddress,
+                        .hopcount = p->hopcount, .size = p->size, .counter = p->counter};
+  return newPacket;
+}
+
+void handle_packet(node_t* n, packet_t* p, uint8_t port) {
+  if (parse_type(p) != BUFFER_UPDATE) {
+    update_LUT(n, p->source, p->hopcount, port);
+  }
+  switch parse_type(p) {
+    case STANDARD:
+      if (p->destination == n.myAddress) {
+        //process
+        //reply
+      } else {
+        p->hopcount++;
+        if (n->LUT[p->destination]) {
+          int bestPort = 0;
+          int bestHopCount = n->LUT[p->destination][0];
+          for (int i = 0; i < 4; i++) {
+            if (n->LUT[p->destination][i] < bestHopCount) {
+              bestPort = i;
+              bestHopCount = n->LUT[p->destination][i];
+            }
+          }
+          send_packet(p, bestPort);
+        } else {
+          broadcast_packet(turn_to_standard_flood(n, p));
+        }
+      }
+      break;
+    case ACK:
+      if (p->destination == n.myAddress) {
+        //process
+      } else {
+        p->hopcount++;
+        if (n->LUT[p->destination]) {
+          int bestPort = 0;
+          int bestHopCount = n->LUT[p->destination][0];
+          for (int i = 0; i < 4; i++) {
+            if (n->LUT[p->destination][i] < bestHopCount) {
+              bestPort = i;
+              bestHopCount = n->LUT[p->destination][i];
+            }
+          }
+          send_packet(p, bestPort);
+        } else {
+          broadcast_packet(turn_to_standard_flood(n, p));
+        }
+      }
+      break;
+    case STANDARD_FLOOD:
+      n->LUT[p->destination][port] = 255;
+      if (p->destination == n.myAddress) {
+        //process
+        //reply
+      } else {
+        p->hopcount++;
+        if (n->LUT[p->destination]) {
+          int bestPort = 0;
+          int bestHopCount = n->LUT[p->destination][0];
+          for (int i = 0; i < 4; i++) {
+            if (n->LUT[p->destination][i] < bestHopCount) {
+              bestPort = i;
+              bestHopCount = n->LUT[p->destination][i];
+            }
+          }
+          send_packet(p, bestPort);
+        } else {
+          broadcast_packet(turn_to_standard_flood(n, p), port);
+        }
+      }
+      break;
+    case ACK_FLOOD:
+    n->LUT[p->destination][port] = 255;
+    if (p->destination == n.myAddress) {
+      //process
+    } else {
+      p->hopcount++;
+      if (n->LUT[p->destination]) {
+        int bestPort = 0;
+        int bestHopCount = n->LUT[p->destination][0];
+        for (int i = 0; i < 4; i++) {
+          if (n->LUT[p->destination][i] < bestHopCount) {
+            bestPort = i;
+            bestHopCount = n->LUT[p->destination][i];
+          }
+        }
+        send_packet(p, bestPort);
+      } else {
+        broadcast_packet(turn_to_standard_flood(n, p), port);
+      }
+    }
+      break;
+    case BUFFER_UPDATE:
+      n->portBufferSizes[port] = p->raw[0];
+      break;
+    default:
+      // not possible
+  }
+}