Updates

src/utils/grab-next-available-port.ts

@@ -0,0 +1,44 @@
+import { dlopen, ptr, FFIType } from "bun:ffi";
+import { AppData } from "../data/app-data";
+
+const libc = dlopen("libc.so.6", {
+    socket: {
+        args: [FFIType.i32, FFIType.i32, FFIType.i32],
+        returns: FFIType.i32,
+    },
+    bind: {
+        args: [FFIType.i32, FFIType.ptr, FFIType.i32],
+        returns: FFIType.i32,
+    },
+    close: { args: [FFIType.i32], returns: FFIType.i32 },
+});
+
+const AF_INET = 2;
+const SOCK_STREAM = 1;
+const INADDR_ANY = 0;
+
+function makeSockaddr(port: number): Buffer {
+    const buf = Buffer.alloc(16);
+    buf.writeUInt16LE(AF_INET, 0);
+    buf.writeUInt16BE(port, 2);
+    buf.writeUInt32BE(INADDR_ANY, 4);
+    return buf;
+}
+
+export default function getNextAvailablePort(
+    startPort = AppData["DynamicPortStart"],
+    maxPort = 65535,
+): number {
+    for (let port = startPort; port <= maxPort; port++) {
+        const fd = libc.symbols.socket(AF_INET, SOCK_STREAM, 0);
+        if (fd < 0) continue;
+
+        const addr = makeSockaddr(port);
+        const result = libc.symbols.bind(fd, ptr(addr), addr.byteLength);
+        libc.symbols.close(fd);
+
+        if (result === 0) return port;
+    }
+
+    throw new Error(`No available port found in range ${startPort}-${maxPort}`);
+}