From 3407774a1a39ca4859d363a2a6a0b78354b309c0 Mon Sep 17 00:00:00 2001
From: Daniel Flanagan <daniel@lyte.dev>
Date: Fri, 24 Jun 2022 23:11:49 -0500
Subject: [PATCH] readme

---
 readme.md   | 20 ++++++++++++++++++++
 tcplexer.ts | 40 +++++++++++++++++++++++++++++++++++++---
 2 files changed, 57 insertions(+), 3 deletions(-)
 create mode 100644 readme.md
 mode change 100644 => 100755 tcplexer.ts

diff --git a/readme.md b/readme.md
new file mode 100644
index 0000000..51a1497
--- /dev/null
+++ b/readme.md
@@ -0,0 +1,20 @@
+# tcplexer
+
+`tcplexer` is a tiny Deno app that receives TCP packets from one socket and
+copies those packets' contents to them all connected clients on another socket.
+
+# Example Usage
+
+```bash
+SOURCE_PORT=7517 CLIENT_PORT=7518 deno run --allow-net --allow-env tcplexer.ts &
+
+ffmpeg -i 'rtsp://admin:pass@10.0.0.104' -vn \
+  -i 'rtsp://admin:pass@10.0.0.222' -vn \
+  -ac 1 -filter_complex amerge=inputs=2 \
+  -hide_banner -loglevel error -f mp3 - \
+    | netcat localhost 7517
+
+vlc 'tcp://localhost:7518'
+```
+
+> TODO: show client with mpv or cvlc or something
diff --git a/tcplexer.ts b/tcplexer.ts
old mode 100644
new mode 100755
index 2899db5..6d2fb7d
--- a/tcplexer.ts
+++ b/tcplexer.ts
@@ -1,10 +1,21 @@
+#!/usr/bin/env -S deno run --allow-net --allow-env
+
 import { iterateReader } from "https://deno.land/std@0.145.0/streams/conversion.ts";
 
 const clients: Set<Deno.Conn> = new Set();
 
 (async () => {
   try {
-    const sourceListener = Deno.listen({ port: 8080 });
+    const sourcePort = parseInt(Deno.env.get("SOURCE_PORT") || "") || 0;
+    const sourceSockOpts = {
+      port: sourcePort,
+    };
+
+    const sourceListener = Deno.listen(sourceSockOpts);
+    console.info(
+      "Listening for source connections on port",
+      (sourceListener.addr as Deno.NetAddr).port,
+    );
     for await (const source of sourceListener) {
       console.info("Source connected from", source.remoteAddr);
       for await (const packet of iterateReader(source)) {
@@ -18,13 +29,23 @@ const clients: Set<Deno.Conn> = new Set();
       console.info(`Source disconnected from`, source.remoteAddr);
     }
   } catch (err) {
-    console.error("Error listening for TCP connections on port 8080:", err);
+    console.error("Error listening for source TCP connections:", err);
+    Deno.exit(1);
   }
 })();
 
 (async () => {
   try {
-    const clientsListener = Deno.listen({ port: 8081 });
+    const clientPort = parseInt(Deno.env.get("CLIENT_PORT") || "") || 0;
+    const clientSockOpts = {
+      port: clientPort,
+    };
+
+    const clientsListener = Deno.listen(clientSockOpts);
+    console.info(
+      "Listening for client connections on port",
+      (clientsListener.addr as Deno.NetAddr).port,
+    );
     while (true) {
       try {
         const conn = await clientsListener.accept();
@@ -38,3 +59,16 @@ const clients: Set<Deno.Conn> = new Set();
     console.error("Error listening for TCP connections on port 8081:", err);
   }
 })();
+
+/* stdin
+(async () => {
+  for await (const packet of iterateReader(Deno.stdin)) {
+    clients.forEach((client, _v2, _set) =>
+      client.write(packet).catch(() => {
+        console.log(`Client disconnected from`, client.remoteAddr);
+        clients.delete(client);
+      })
+    );
+  }
+})();
+*/