From 73b93d99af0f016bde46d7f5688993b41a89fadc Mon Sep 17 00:00:00 2001
From: _ <>
Date: Fri, 26 Nov 2021 21:46:27 +0000
Subject: [PATCH] :hatching_chick: so that's how multicast groups work

---
 .gitignore  |  1 +
 Cargo.lock  | 16 ++++++++++++++++
 Cargo.toml  |  9 +++++++++
 src/main.rs | 52 ++++++++++++++++++++++++++++++++++++++++++++++++++++
 4 files changed, 78 insertions(+)
 create mode 100644 .gitignore
 create mode 100644 Cargo.lock
 create mode 100644 Cargo.toml
 create mode 100644 src/main.rs

diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..ea8c4bf
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1 @@
+/target
diff --git a/Cargo.lock b/Cargo.lock
new file mode 100644
index 0000000..1305cbb
--- /dev/null
+++ b/Cargo.lock
@@ -0,0 +1,16 @@
+# This file is automatically @generated by Cargo.
+# It is not intended for manual editing.
+version = 3
+
+[[package]]
+name = "anyhow"
+version = "1.0.48"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "62e1f47f7dc0422027a4e370dd4548d4d66b26782e513e98dca1e689e058a80e"
+
+[[package]]
+name = "lookaround"
+version = "0.1.0"
+dependencies = [
+ "anyhow",
+]
diff --git a/Cargo.toml b/Cargo.toml
new file mode 100644
index 0000000..1dbe791
--- /dev/null
+++ b/Cargo.toml
@@ -0,0 +1,9 @@
+[package]
+name = "lookaround"
+version = "0.1.0"
+edition = "2021"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]
+anyhow = "1.0.48"
diff --git a/src/main.rs b/src/main.rs
new file mode 100644
index 0000000..f2a6b6f
--- /dev/null
+++ b/src/main.rs
@@ -0,0 +1,52 @@
+use std::{
+	env,
+	net::{
+		Ipv4Addr,
+		UdpSocket,
+	},
+	str::FromStr,
+};
+
+use anyhow::{
+	self,
+	Result,
+	bail,
+};
+
+fn main () -> Result <()> {
+	let mut args = env::args ();
+	
+	let _exe_name = args.next ();
+	
+	match args.next ().as_ref ().map (|s| &s[..]) {
+		None => bail! ("First argument must be a subcommand"),
+		Some ("client") => client ()?,
+		Some ("server") => server ()?,
+		Some (x) => bail! ("Unknown subcommand {}", x),
+	}
+	
+	Ok (())
+}
+
+fn client () -> Result <()> {
+	let socket = UdpSocket::bind ("0.0.0.0:9041").unwrap ();
+	
+	socket.join_multicast_v4 (&(Ipv4Addr::from_str ("225.100.99.98").unwrap ()), &([0u8, 0, 0, 0].into ())).unwrap ();
+	
+	socket.send_to ("hi there".as_bytes (), ("225.100.99.98", 9040)).unwrap ();
+	
+	Ok (())
+}
+
+fn server () -> Result <()> {
+	let socket = UdpSocket::bind ("0.0.0.0:9040").unwrap ();
+	
+	socket.join_multicast_v4 (&(Ipv4Addr::from_str ("225.100.99.98").unwrap ()), &([0u8, 0, 0, 0].into ())).unwrap ();
+	
+	let mut buf = vec! [0u8; 4096];
+	let (bytes_recved, remote_addr) = socket.recv_from (&mut buf).unwrap ();
+	
+	dbg! (bytes_recved, remote_addr);
+	
+	Ok (())
+}