Introduce devices interfaces into rounting tables and forwarding packets logic (#230)

MAC and IP addresses are now just in device interfaces and the forwarding logic is based on the sending interfaces instead of the next hop device.

Author: Manuel-Pol

src/context.ts

@@ -41,6 +41,9 @@ export class GlobalContext {
     return this.ipGenerator.getNextIp();
   }
 
+  getMask(): string {
+    return this.ipGenerator.getMask();
+  }
   getNextMac(): string {
     return this.macGenerator.getNextMac();
   }
@@ -178,9 +181,11 @@ export class GlobalContext {
 
     for (const [, device] of this.datagraph.getDevices()) {
       if (device instanceof DataNetworkDevice) {
-        if (compareIps(maxIp, device.ip) < 0) {
-          maxIp = device.ip;
-        }
+        device.interfaces.forEach((iface) => {
+          if (iface.ip && compareIps(maxIp, iface.ip) < 0) {
+            maxIp = iface.ip;
+          }
+        });
       }
     }
     const baseIp = maxIp.toString();
@@ -191,9 +196,11 @@ export class GlobalContext {
   private setMacGenerator() {
     let maxMac = MacAddress.parse("00:00:10:00:00:00");
     for (const [, device] of this.datagraph.getDevices()) {
-      if (compareMacs(maxMac, device.mac) < 0) {
-        maxMac = device.mac;
-      }
+      device.interfaces.forEach((iface) => {
+        if (compareMacs(maxMac, iface.mac) < 0) {
+          maxMac = iface.mac;
+        }
+      });
     }
     // TODO: we should use MacAddress instead of string here and in Datagraph
     const baseMac = maxMac.toString();

src/graphics/renderables/device_info.ts

@@ -29,7 +29,7 @@ export class DeviceInfo extends BaseInfo {
   }
 
   protected addCommonInfoFields(): void {
-    const { id, mac } = this.device;
+    const { id } = this.device;
     const connections = this.device.viewgraph.getVisibleConnectedDeviceIds(id);
 
     this.information.addField(TOOLTIP_KEYS.ID, id.toString(), TOOLTIP_KEYS.ID);
@@ -42,10 +42,12 @@ export class DeviceInfo extends BaseInfo {
     const layer = this.device.viewgraph.getLayer();
 
     if (layer == Layer.Link) {
-      this.information.addField(
-        TOOLTIP_KEYS.MAC_ADDRESS,
-        mac.toString(),
-        TOOLTIP_KEYS.MAC_ADDRESS,
+      this.device.interfaces.forEach((iface) =>
+        this.information.addField(
+          TOOLTIP_KEYS.MAC_ADDRESS,
+          iface.mac.toString(),
+          TOOLTIP_KEYS.MAC_ADDRESS,
+        ),
       );
     }
   }

src/graphics/renderables/edge_info.ts

@@ -53,12 +53,12 @@ export class EdgeInfo extends BaseInfo {
     // Add MAC addresses as separate fields
     this.information.addField(
       `MAC Address iface (Device ${from})`,
-      fromInterface.mac.octets.join(":"),
+      fromInterface.mac.toString(),
       TOOLTIP_KEYS.MAC_ADDRESS_IFACE,
     );
     this.information.addField(
       `MAC Address iface (Device ${to})`,
-      toInterface.mac.octets.join(":"),
+      toInterface.mac.toString(),
       TOOLTIP_KEYS.MAC_ADDRESS_IFACE,
     );
   }

src/graphics/renderables/program_info.ts

@@ -71,7 +71,13 @@ function otherDevices(viewgraph: ViewGraph, srcId: DeviceId) {
     .map((id) => ({ value: id.toString(), text: `Device ${id}`, id }));
 }
 
-function otherDevicesIp(viewgraph: ViewGraph, srcId: DeviceId) {
+function otherDevicesIp(
+  viewgraph: ViewGraph,
+  srcId: DeviceId,
+): {
+  value: string;
+  text: string;
+}[] {
   return viewgraph
     .getDevices()
     .filter(
@@ -80,12 +86,10 @@ function otherDevicesIp(viewgraph: ViewGraph, srcId: DeviceId) {
         device.getType() !== DeviceType.Switch &&
         device.id !== srcId,
     )
-    .map((device) => {
-      if ("ip" in device) {
-        const ipString = device.ip.toString();
-        return { value: ipString, text: `${ipString} (Device ${device.id})` };
-      }
-      // Shouldn’t get here
-      return { value: "", text: "" };
+    .flatMap((device) => {
+      return device.interfaces.map((iface) => ({
+        value: iface.ip.toString(),
+        text: `${iface.ip.toString()} (Device ${device.id})`,
+      }));
     });
 }

src/packets/ip.ts

@@ -111,6 +111,13 @@ export class IpAddressGenerator {
     return { ip: nextIp, mask: this.mask };
   }
 
+  /**
+   * Return the mask used by the IpAddressGenerator
+   */
+  getMask(): string {
+    return this.mask;
+  }
+
   // Turn IP into a number
   static ipToNumber(ip: string): number {
     return ip

src/programs/arp_protocol.ts

@@ -46,29 +46,20 @@ export class ArpProtocol extends ProgramBase {
   private sendRequest() {
     const srcDevice = this.viewgraph.getDevice(this.srcId);
     if (!(srcDevice instanceof ViewNetworkDevice)) {
-      console.log(
-        "At least one device between source and destination is not a network device",
-      );
+      console.error("Source device is not a network device");
       return;
     }
     const connections = this.viewgraph.getConnections(this.srcId);
     connections.forEach((edge) => {
-      const payload: FramePayload = new ArpRequest(
-        srcDevice.mac,
-        srcDevice.ip,
-        this.dstIp,
-      );
+      const ifaceNum = edge.getDeviceInterface(this.srcId);
+      const { mac, ip } = srcDevice.interfaces[ifaceNum];
+      const payload: FramePayload = new ArpRequest(mac, ip, this.dstIp);
       const ethernetFrame = new EthernetFrame(
-        srcDevice.mac,
+        mac,
         MacAddress.broadcastAddress(),
         payload,
       );
-      sendViewPacket(
-        this.viewgraph,
-        this.srcId,
-        ethernetFrame,
-        edge.otherEnd(this.srcId),
-      );
+      sendViewPacket(this.viewgraph, this.srcId, ethernetFrame, ifaceNum);
     });
   }
 

src/programs/echo_sender.ts

@@ -50,32 +50,27 @@ export class SingleEcho extends ProgramBase {
       );
       return;
     }
+    const { src, dst, sendingIface } = ViewNetworkDevice.getForwardingData(
+      this.srcId,
+      this.dstId,
+      this.viewgraph,
+    );
     const echoRequest = new EchoRequest(0);
     // Wrap in IP datagram
-    const ipPacket = new IPv4Packet(srcDevice.ip, dstDevice.ip, echoRequest);
+    const ipPacket = new IPv4Packet(src.ip, dst.ip, echoRequest);
 
     // Resolve destination MAC address
-    let dstMac = srcDevice.resolveAddress(dstDevice.ip);
+    const dstMac = srcDevice.resolveAddress(dst.ip);
     if (!dstMac) {
       console.warn(
-        `Device ${this.srcId} couldn't resolve MAC address for device with IP ${dstDevice.ip.toString()}. Program cancelled`,
+        `Device ${this.srcId} couldn't resolve MAC address for device with IP ${dst.ip.toString()}. Program cancelled`,
       );
       return;
     }
-    const path = this.viewgraph.getPathBetween(this.srcId, this.dstId);
-    if (!path) return;
-    for (const id of path.slice(1)) {
-      const device = this.viewgraph.getDevice(id);
-      // if there’s a router in the middle, first send frame to router mac
-      if (device instanceof ViewNetworkDevice) {
-        dstMac = device.mac;
-        break;
-      }
-    }
 
     // Wrap in Ethernet frame
-    const ethernetFrame = new EthernetFrame(srcDevice.mac, dstMac, ipPacket);
-    sendViewPacket(this.viewgraph, this.srcId, ethernetFrame);
+    const ethernetFrame = new EthernetFrame(src.mac, dst.mac, ipPacket);
+    sendViewPacket(this.viewgraph, this.srcId, ethernetFrame, sendingIface);
   }
 
   static getProgramInfo(viewgraph: ViewGraph, srcId: DeviceId): ProgramInfo {

src/programs/http_client.ts

@@ -74,8 +74,9 @@ export class HttpClient extends ProgramBase {
     }
 
     // Encode HTTP request
+    // NOTE: For now, as hosts have just one interface, destination ip is hardcoded
     const httpRequest = getContentRequest(
-      this.runner.ip.toString(),
+      this.runner.interfaces[0].toString(),
       this.resource,
     );
 

src/types/data-devices/dDevice.ts

@@ -1,15 +1,15 @@
 import { EthernetFrame, MacAddress } from "../../packets/ethernet";
-import { DataGraph, DataNode, DeviceId } from "../graphs/datagraph";
+import { DataGraph, DataNode } from "../graphs/datagraph";
 import { DeviceType, NetworkInterface } from "../view-devices/vDevice";
 import { Position } from "../common";
+import { IpAddress } from "../../packets/ip";
 
 export abstract class DataDevice {
   private static idCounter = 1;
 
   id: number;
   x: number;
   y: number;
-  mac: MacAddress;
   datagraph: DataGraph;
   interfaces: NetworkInterface[] = [];
 
@@ -22,7 +22,6 @@ export abstract class DataDevice {
   constructor(graphData: DataNode, datagraph: DataGraph) {
     this.x = graphData.x;
     this.y = graphData.y;
-    this.mac = MacAddress.parse(graphData.mac);
     if (graphData.id) {
       this.id = graphData.id;
       DataDevice.setIdCounter(graphData.id);
@@ -33,6 +32,7 @@ export abstract class DataDevice {
       this.interfaces.push({
         name: iface.name,
         mac: MacAddress.parse(iface.mac),
+        ip: iface.ip !== undefined ? IpAddress.parse(iface.ip) : undefined,
       });
     });
     this.datagraph = datagraph;
@@ -48,16 +48,20 @@ export abstract class DataDevice {
       type: this.getType(),
       x: this.x,
       y: this.y,
-      mac: this.mac.toString(),
       interfaces: this.interfaces.map((iface) => ({
         name: iface.name,
         mac: iface.mac.toString(),
+        ip: iface.ip !== undefined ? iface.ip.toString() : undefined,
       })),
     };
   }
 
   abstract getType(): DeviceType;
 
+  ownMac(mac: MacAddress): boolean {
+    return this.interfaces.some((iface) => iface.mac.equals(mac));
+  }
+
   getPosition(): Position {
     return { x: this.x, y: this.y };
   }
@@ -66,5 +70,5 @@ export abstract class DataDevice {
    * Returns the id for the next device to send the packet to, or
    * null if there’s no next device to send the packet.
    * */
-  abstract receiveFrame(frame: EthernetFrame, senderId: DeviceId): void;
+  abstract receiveFrame(frame: EthernetFrame, iface: number): void;
 }

src/types/data-devices/dHost.ts

@@ -25,7 +25,7 @@ export class DataHost extends DataNetworkDevice {
     if (!(datagram instanceof IPv4Packet)) {
       return null;
     }
-    if (this.ip.equals(datagram.destinationAddress)) {
+    if (this.ownIp(datagram.destinationAddress)) {
       this.handlePacket(datagram);
     }
   }