From 3ecfe8a05b854bd30f8897c8542c40791002d99e Mon Sep 17 00:00:00 2001
From: Takeru Ohta <phjgt308@gmail.com>
Date: Mon, 12 Feb 2024 21:39:55 +0900
Subject: [PATCH] Add `RpcClient::connect_with_port()` to support epmdless
 nodes

---
 examples/call-zero-arity-fun.rs | 10 +++++++++-
 src/lib.rs                      | 17 +++++++++++++----
 2 files changed, 22 insertions(+), 5 deletions(-)

diff --git a/examples/call-zero-arity-fun.rs b/examples/call-zero-arity-fun.rs
index 7309884..4af5e12 100644
--- a/examples/call-zero-arity-fun.rs
+++ b/examples/call-zero-arity-fun.rs
@@ -9,6 +9,9 @@ struct Args {
 
     #[clap(long)]
     cookie: Option<String>,
+
+    #[clap(long, short)]
+    port: Option<u16>,
 }
 
 fn main() -> anyhow::Result<()> {
@@ -22,7 +25,12 @@ fn main() -> anyhow::Result<()> {
     };
 
     smol::block_on(async {
-        let client = erl_rpc::RpcClient::connect(&args.node_name.to_string(), &cookie).await?;
+        let client = if let Some(port) = args.port {
+            erl_rpc::RpcClient::connect_with_port(&args.node_name.to_string(), port, &cookie)
+                .await?
+        } else {
+            erl_rpc::RpcClient::connect(&args.node_name.to_string(), &cookie).await?
+        };
         let mut handle = client.handle();
         smol::spawn(async {
             if let Err(e) = client.run().await {
diff --git a/src/lib.rs b/src/lib.rs
index b4d13f4..3e963e7 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -99,12 +99,22 @@ pub struct RpcClient {
 impl RpcClient {
     /// Connects to a given Erlang node.
     pub async fn connect(server_node_name: &str, cookie: &str) -> Result<Self, ConnectError> {
-        let server_node_name: NodeName = server_node_name.parse()?;
-        let server_node_entry = get_node_entry(&server_node_name).await?;
+        let server_node_entry = get_node_entry(&server_node_name.parse()?).await?;
         if server_node_entry.highest_version < 6 {
             return Err(ConnectError::TooOldDistributionProtocolVersion);
         }
 
+        Self::connect_with_port(server_node_name, server_node_entry.port, cookie).await
+    }
+
+    /// Directly connects to a given Erlang node without using EPMD.
+    ///
+    pub async fn connect_with_port(
+        server_node_name: &str,
+        server_listen_port: u16,
+        cookie: &str,
+    ) -> Result<Self, ConnectError> {
+        let server_node_name: NodeName = server_node_name.parse()?;
         let tentative_name = "nonode@localhost";
         let mut local_node = LocalNode::new(tentative_name.parse()?, Creation::random());
         local_node.flags |= DistributionFlags::NAME_ME;
@@ -112,8 +122,7 @@ impl RpcClient {
         local_node.flags |= DistributionFlags::DIST_MONITOR;
         local_node.flags |= DistributionFlags::DIST_MONITOR_NAME;
 
-        let connection =
-            TcpStream::connect((server_node_name.host(), server_node_entry.port)).await?;
+        let connection = TcpStream::connect((server_node_name.host(), server_listen_port)).await?;
         let mut handshake = ClientSideHandshake::new(connection, local_node.clone(), cookie);
         let status = handshake.execute_send_name(6).await?;
         if let HandshakeStatus::Named { name, creation } = status {