init

workers/session-proxy/index.ts

@@ -0,0 +1,66 @@
+import IPParser from "./ip-parser";
+import blockList from "./block-list-ipv4.txt";
+
+interface Env {
+  KV_STORAGE: KVNamespace;
+  WORKER_SITE: Fetcher;
+}
+
+export default {
+  async fetch(request: Request, env: Env): Promise<Response> {
+    try {
+      const ip = getIp(request);
+      if (ip !== "::1") {
+        return await runVpnBlocker(request, env);
+      } else {
+        return forwardRequest(request, env);
+      }
+    } catch (e) {
+      throw "Server Error";
+    }
+  },
+} satisfies ExportedHandler<Env>;
+
+function forwardRequest(request, env) {
+  // Forward the request to the origin
+  return env.WORKER_SITE.fetch(request);
+}
+
+const getIp = (request) => {
+  try {
+    try {
+      const ipv4 = IPParser.parseIP(request.headers.get("CF-Connecting-IP"));
+      return ipv4;
+    } catch (e) {
+      const v6ToV4 = IPParser.parseIP(request.headers.get("Cf-Pseudo-IPv4"));
+      return v6ToV4;
+    }
+  } catch (e) {
+    const fallback = request.headers.get("CF-Connecting-IP") as string;
+    if (!fallback) {
+      throw "Missing CF-Connecting-IP header";
+    }
+    return fallback;
+  }
+};
+
+function runVpnBlocker(request, env) {
+  const reqIp = getIp(request).join(".");
+
+  if (!reqIp) {
+    return new Response("Missing IP address", { status: 400 });
+  }
+
+  const blockListContent: string = blockList as unknown as string;
+
+  const blocked = blockListContent
+    .split("\n")
+    .some((cidr: string) => IPParser.isInRange(reqIp, cidr));
+
+  if (blocked) {
+    return new Response("Access Denied.\nReason: VPN Detected!\nCode: 403", {
+      status: 403,
+    });
+  }
+  return forwardRequest(request, env);
+}