WSL: Handle eth0 being renamed

Signed-off-by: Mark Yen <mark.yen@suse.com>

.github/actions/spelling/expect.txt

@@ -371,6 +371,7 @@ INSTALLPROPERTY
 ioctl
 ipaddr
 iptable
+IRTT
 Isf
 isthebestmeshuggahalbum
 istio

.github/actions/spelling/patterns.txt

@@ -5,10 +5,6 @@
 # ANSI color codes
 (?:\\(?:u00|x)1[Bb]|\x1b|\\u\{1[Bb]\})\[\d+(?:;\d+|)m
 
-# hit-count: 743 file-count: 13
-# hex runs
-\b[0-9a-fA-F]{16,}\b
-
 # hit-count: 739 file-count: 6
 # base64 encoded content, possibly wrapped in mime
 (?:^|[\s=;:?])[-a-zA-Z=;:/0-9+]{50,}(?:[\s=;:?]|$)
@@ -42,6 +38,11 @@ sha\d+:[0-9]*[a-f]{3,}[0-9a-f]*
 # uuid:
 \b[0-9a-fA-F]{8}-(?:[0-9a-fA-F]{4}-){3}[0-9a-fA-F]{12}\b
 
+# hit-count: 743 file-count: 13
+# hex runs
+\b[0-9a-fA-F]{16,}\b
+\b[0-9A-F]{8,}\b
+
 # hit-count: 10 file-count: 1
 # css url wrappings
 \burl\([^)]+\)

pkg/rancher-desktop/backend/__tests__/wsl.spec.ts

@@ -0,0 +1,75 @@
+import WSLBackend from '../wsl';
+
+describe('WSLBackend', () => {
+  describe('getIPAddress', () => {
+    const route = `
+      Iface   Destination     Gateway         Flags   RefCnt  Use     Metric  Mask            MTU     Window  IRTT
+      eth0    00000000        01F019AC        0003    0       0       0       00000000        0       0       0
+      docker0 000011AC        00000000        0001    0       0       0       0000FFFF        0       0       0
+      eth0    00F019AC        00000000        0001    0       0       0       00F0FFFF        0       0       0
+    `;
+    const trie = `
+        +-- 0.0.0.0/0 3 0 5
+          |-- 0.0.0.0
+              /0 universe UNICAST
+          +-- 127.0.0.0/8 2 0 2
+              +-- 127.0.0.0/31 1 0 0
+                |-- 127.0.0.0
+                    /8 host LOCAL
+                |-- 127.0.0.1
+                    /32 host LOCAL
+              |-- 127.255.255.255
+                /32 link BROADCAST
+          +-- 172.16.0.0/12 2 0 2
+              +-- 172.17.0.0/16 2 0 2
+                +-- 172.17.0.0/31 1 0 0
+                    |-- 172.17.0.0
+                      /16 link UNICAST
+                    |-- 172.17.0.1
+                      /32 host LOCAL
+                |-- 172.17.255.255
+                    /32 link BROADCAST
+              +-- 172.25.240.0/20 2 0 2
+                +-- 172.25.240.0/23 2 0 2
+                    |-- 172.25.240.0
+                      /20 link UNICAST
+                    |-- 172.25.241.207
+                      /32 host LOCAL
+                |-- 172.25.255.255
+                    /32 link BROADCAST
+    `;
+
+    it('should return an IP address', async() => {
+      function readFile(fileName: string): Promise<string> {
+        if (fileName === '/proc/net/route') {
+          return Promise.resolve(route);
+        }
+        if (fileName === '/proc/net/fib_trie') {
+          return Promise.resolve(`Main:\n${ trie }Local:\n${ trie }`);
+        }
+
+        return Promise.reject(new Error(`Read unexpected file ${ fileName }`));
+      }
+      const expected = '172.25.241.207';
+      const actual = WSLBackend.prototype['getIPAddress'].call(null, readFile);
+
+      await expect(actual).resolves.toEqual(expected);
+    });
+    it('should accept non-standard network interface name', async() => {
+      function readFile(fileName: string): Promise<string> {
+        if (fileName === '/proc/net/route') {
+          return Promise.resolve(route.replaceAll('eth0', 'eth3'));
+        }
+        if (fileName === '/proc/net/fib_trie') {
+          return Promise.resolve(`Main:\n${ trie }Local:\n${ trie }`);
+        }
+
+        return Promise.reject(new Error(`Read unexpected file ${ fileName }`));
+      }
+      const expected = '172.25.241.207';
+      const actual = WSLBackend.prototype['getIPAddress'].call(null, readFile);
+
+      await expect(actual).resolves.toEqual(expected);
+    });
+  });
+});

pkg/rancher-desktop/backend/wsl.ts

@@ -950,23 +950,63 @@ export default class WSLBackend extends events.EventEmitter implements VMBackend
         // wslinfo is missing (wsl < 2.0.4) - fall back to old behavior
       }
 
-      // We need to locate the _local_ route (netmask) for eth0, and then
-      // look it up in /proc/net/fib_trie to find the local address.
-      const routesString = await this.captureCommand('cat', '/proc/net/route');
-      const routes = routesString.split(/\r?\n/).map(line => line.split(/\s+/));
-      const route = routes.find(route => route[0] === 'eth0' && route[1] !== '00000000');
+      return this.getIPAddress();
+    })();
+  }
+
+  // Get the IP address of the VM by reading files in /proc/net
+  // This is used to implement the `ipAddress` getter; it's only a separate
+  // method to make testing easier.
+  protected async getIPAddress(readFile?: (fileName: string) => Promise<string>): Promise<string | undefined> {
+    readFile ??= fileName => this.captureCommand('cat', fileName);
+
+    // Look at all local addresses in `/proc/net/fib_trie`, then try to find
+    // the best fit one (and blacklist `docker0`, `cni0`, `veth-rd-ns`).
+    const trieContents = await readFile('/proc/net/fib_trie');
+    const trieLines = trieContents.split(/\r?\n/).reverse();
+    // localIndices refer to the lines that say "/32 host LOCAL", i.e. interface addresses.
+    const localIndices = Array.from(trieLines.entries()).filter(([, line]) => line.includes('/32 host LOCAL')).map(([i]) => i);
+    // addresses is the actual IP addresses of the local interfaces.
+    const addresses = localIndices.map(i => trieLines[i + 1].trim().split(/\s+/).pop() ?? '127.0.0.1');
+    // masks is the network mask for each IP address.
+    const masks = localIndices.map((i) => {
+      return trieLines.find((line, j) => {
+        // Find the next line that starts with '+'.
+        return j > i && line.trim().startsWith('+');
+      })?.split(/\s+/).find(w => w.includes('/'))?.split('/')
+        .shift() ?? '127.0.0.1'; // Extract the IP address.
+    });
 
-      if (!route) {
+    const routeContents = await readFile('/proc/net/route');
+    const routes = routeContents.split(/\r?\n/).map((line) => {
+      const [iface, destination] = line.trim().split(/\s+/);
+
+      if (!iface || !destination) {
         return undefined;
       }
-      const net = Array.from(route[1].matchAll(/../g)).reverse().map(n => parseInt(n.toString(), 16)).join('.');
-      const trie = await this.captureCommand('cat', '/proc/net/fib_trie');
-      const lines = _.takeWhile(trie.split(/\r?\n/).slice(1), line => /^\s/.test(line));
-      const iface = _.dropWhile(lines, line => !line.includes(`${ net }/`));
-      const addr = iface.find((_, i, array) => array[i + 1]?.includes('/32 host LOCAL'));
+      const mask = Array.from(destination.matchAll(/../g)).reverse().map(([v]) => parseInt(v, 16)).join('.');
 
-      return addr?.split(/\s+/).pop();
-    })();
+      return [mask, iface];
+    }).filter(defined);
+
+    for (const i in localIndices) {
+      const mask = masks[i];
+
+      if (!mask || mask.startsWith('127.') || mask === '0.0.0.0') {
+        // Invalid mask, localhost mask, or external.
+        continue;
+      }
+      const iface = routes.find(([routeMask]) => mask === routeMask)?.[1];
+
+      if (!iface || /^(cni\d|docker\d|veth)/.test(iface)) {
+        continue;
+      }
+      const address = addresses[i];
+
+      if (address) {
+        return address;
+      }
+    }
   }
 
   async getBackendInvalidReason(): Promise<BackendError | null> {