From cafa84df5892ae5fd854b5f8e9e81e369832869b Mon Sep 17 00:00:00 2001
From: upmcplanetracker <219436948+upmcplanetracker@users.noreply.github.com>
Date: Sat, 19 Sep 2026 07:29:50 -0400
Subject: [PATCH 1/3] Update Cargo.toml

---
 Cargo.toml | 1 +
 1 file changed, 1 insertion(+)

diff --git a/Cargo.toml b/Cargo.toml
index 6451f08..9713594 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -24,6 +24,7 @@ rand = "0.9.0"
 rbtag = "0.3.0"
 serde = { version = "1.0.217", features = ["derive"] }
 serde_json = "1.0.138"
+socket2 = "0.5"
 strum = "0.27.1"
 strum_macros = "0.27.1"
 thiserror = "2.0.11"

From 4a4812b90aee0fc1b2be9b2bac54ae6747090120 Mon Sep 17 00:00:00 2001
From: upmcplanetracker <219436948+upmcplanetracker@users.noreply.github.com>
Date: Sat, 19 Sep 2026 07:32:54 -0400
Subject: [PATCH 2/3] Update Cargo.lock

---
 Cargo.lock | 1 +
 1 file changed, 1 insertion(+)

diff --git a/Cargo.lock b/Cargo.lock
index 2707d8b..8e88951 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -2696,6 +2696,7 @@ dependencies = [
  "rbtag",
  "serde",
  "serde_json",
+ "socket2",
  "strum 0.27.1",
  "strum_macros 0.27.1",
  "thiserror 2.0.11",

From bbdb8c7bf718aed794b8ca07ffebb69c79e14168 Mon Sep 17 00:00:00 2001
From: upmcplanetracker <ID+username@users.noreply.github.com>
Date: Sat, 19 Sep 2026 07:42:44 -0400
Subject: [PATCH 3/3] Bind dual-stack ([::]) with IPv4 fallback

---
 src/http/mod.rs | 43 ++++++++++++++++++++++++++++++++++++-------
 1 file changed, 36 insertions(+), 7 deletions(-)

diff --git a/src/http/mod.rs b/src/http/mod.rs
index 86928c5..09dc09d 100644
--- a/src/http/mod.rs
+++ b/src/http/mod.rs
@@ -1,13 +1,42 @@
+use std::net::{Ipv4Addr, Ipv6Addr, SocketAddr, TcpListener};
+
 use actix_cors::Cors;
 use actix_web::{web, App, HttpServer};
-use log::info;
+use log::{info, warn};
 use services::{download::download, upload::upload, version::version, websocket::websocket};
+use socket2::{Domain, Protocol, Socket, Type};
 
 use crate::http::services::keep::keep;
 
 mod response;
 mod services;
 
+/// Binds a dual-stack listener on `[::]:port` that accepts both IPv6 and IPv4
+/// (via IPv4-mapped addresses). If IPv6 is unavailable (e.g. disabled in the
+/// container), falls back to an IPv4-only listener on `0.0.0.0:port`.
+fn bind_dual_stack(port: u16) -> std::io::Result<TcpListener> {
+    let v6 = (|| -> std::io::Result<Socket> {
+        let socket = Socket::new(Domain::IPV6, Type::STREAM, Some(Protocol::TCP))?;
+        // Explicitly accept IPv4 too; the OS default differs (e.g. Windows/BSD).
+        socket.set_only_v6(false)?;
+        #[cfg(unix)]
+        socket.set_reuse_address(true)?;
+        socket.bind(&SocketAddr::from((Ipv6Addr::UNSPECIFIED, port)).into())?;
+        socket.listen(1024)?;
+        Ok(socket)
+    })();
+
+    let listener = match v6 {
+        Ok(socket) => TcpListener::from(socket),
+        Err(e) => {
+            warn!("IPv6 dual-stack bind failed ({e}); falling back to 0.0.0.0:{port}");
+            TcpListener::bind((Ipv4Addr::UNSPECIFIED, port))?
+        }
+    };
+    listener.set_nonblocking(true)?;
+    Ok(listener)
+}
+
 pub async fn start_http() -> anyhow::Result<()> {
     let server = HttpServer::new(|| {
         App::new()
@@ -27,11 +56,11 @@ pub async fn start_http() -> anyhow::Result<()> {
             )
     });
     let port = std::env::var("PORT").unwrap_or_else(|_| "24153".to_string());
-    if !port.chars().all(char::is_numeric) {
-        anyhow::bail!("PORT must be a number");
-    }
-    let ip = format!("0.0.0.0:{}", port);
-    info!("http server listening on {}", ip);
-    server.bind(ip)?.run().await?;
+    let port: u16 = port
+        .parse()
+        .map_err(|_| anyhow::anyhow!("PORT must be a number between 0 and 65535"))?;
+    let listener = bind_dual_stack(port)?;
+    info!("http server listening on {}", listener.local_addr()?);
+    server.listen(listener)?.run().await?;
     Ok(())
 }