From ed193a3ba5201cb97625669dd09f47e9c1a65a94 Mon Sep 17 00:00:00 2001
From: Julian Braha <julianbraha@gmail.com>
Date: Mon, 13 May 2024 03:35:54 +0100
Subject: [PATCH] Improve Tunnel error handling (#2479)

p2p: create and use TunnelError enum
---
 Cargo.lock                      |  1 +
 crates/p2p-tunnel/Cargo.toml    |  1 +
 crates/p2p-tunnel/src/tunnel.rs | 24 +++++++++++++++++-------
 3 files changed, 19 insertions(+), 7 deletions(-)

diff --git a/Cargo.lock b/Cargo.lock
index 185f1b9ec..b80625c51 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -9455,6 +9455,7 @@ name = "sd-p2p-tunnel"
 version = "0.1.0"
 dependencies = [
  "sd-p2p",
+ "thiserror",
  "tokio",
 ]
 
diff --git a/crates/p2p-tunnel/Cargo.toml b/crates/p2p-tunnel/Cargo.toml
index de13cbab9..e4e0df7bc 100644
--- a/crates/p2p-tunnel/Cargo.toml
+++ b/crates/p2p-tunnel/Cargo.toml
@@ -11,3 +11,4 @@ repository.workspace = true
 sd-p2p = { path = "../p2p" }
 
 tokio = { workspace = true, features = ["io-util"] }
+thiserror = { workspace = true }
diff --git a/crates/p2p-tunnel/src/tunnel.rs b/crates/p2p-tunnel/src/tunnel.rs
index 9a83c4e9e..ae559c158 100644
--- a/crates/p2p-tunnel/src/tunnel.rs
+++ b/crates/p2p-tunnel/src/tunnel.rs
@@ -6,34 +6,44 @@ use std::{
 
 use tokio::io::{AsyncRead, AsyncReadExt, AsyncWrite, AsyncWriteExt, ReadBuf};
 
+use thiserror::Error;
+
 use sd_p2p::UnicastStream;
 
+#[derive(Debug, Error)]
+pub enum TunnelError {
+	#[error("Error writing discriminator.")]
+	DiscriminatorWriteError,
+	#[error("Error reading discriminator. Is this stream actually a tunnel?")]
+	DiscriminatorReadError,
+	#[error("Invalid discriminator. Is this stream actually a tunnel?")]
+	InvalidDiscriminator,
+}
+
 #[derive(Debug)]
 pub struct Tunnel {
 	stream: UnicastStream,
 }
 
 impl Tunnel {
-	// TODO: Proper errors
-	pub async fn initiator(mut stream: UnicastStream) -> Result<Self, &'static str> {
+	pub async fn initiator(mut stream: UnicastStream) -> Result<Self, TunnelError> {
 		stream
 			.write_all(&[b'T'])
 			.await
-			.map_err(|_| "Error writing discriminator")?;
+			.map_err(|_| TunnelError::DiscriminatorWriteError)?;
 
 		// TODO: Do pairing + authentication
 
 		Ok(Self { stream })
 	}
 
-	// TODO: Proper errors
-	pub async fn responder(mut stream: UnicastStream) -> Result<Self, &'static str> {
+	pub async fn responder(mut stream: UnicastStream) -> Result<Self, TunnelError> {
 		let discriminator = stream
 			.read_u8()
 			.await
-			.map_err(|_| "Error reading discriminator. Is this stream actually a tunnel?")?;
+			.map_err(|_| TunnelError::DiscriminatorReadError)?;
 		if discriminator != b'T' {
-			return Err("Invalid discriminator. Is this stream actually a tunnel?");
+			return Err(TunnelError::InvalidDiscriminator);
 		}
 
 		// TODO: Do pairing + authentication