From 511305152ff95af4faf279e960b6bdcf65ab5a99 Mon Sep 17 00:00:00 2001
From: Matt Corallo <git@bluematt.me>
Date: Thu, 2 Jan 2020 20:05:17 -0500
Subject: [PATCH] Add a helper struct to allow a user to safely pass in an addr
 list

---
 lightning/src/ln/msgs.rs | 50 ++++++++++++++++++++++++++++++++++++++++
 1 file changed, 50 insertions(+)

diff --git a/lightning/src/ln/msgs.rs b/lightning/src/ln/msgs.rs
index 8d23ac9a8..04bd85179 100644
--- a/lightning/src/ln/msgs.rs
+++ b/lightning/src/ln/msgs.rs
@@ -306,6 +306,56 @@ impl NetAddress {
 	}
 }
 
+/// A "set" of addresses which enforces that there can be only up to one of each net address type.
+pub struct NetAddressSet {
+	v4: Option<NetAddress>,
+	v6: Option<NetAddress>,
+	onion2: Option<NetAddress>,
+	onion3: Option<NetAddress>,
+}
+impl NetAddressSet {
+	/// Creates a new, empty, NetAddressSet
+	pub fn new() -> Self {
+		NetAddressSet { v4: None, v6: None, onion2: None, onion3: None }
+	}
+
+	/// Sets the IPv4 socket address in this set, overwriting any previous IPv4 socket address.
+	pub fn set_v4(&mut self, addr: [u8; 4], port: u16) {
+		self.v4 = Some(NetAddress::IPv4 { addr, port });
+	}
+	/// Sets the IPv6 socket address in this set, overwriting any previous IPv6 socket address.
+	pub fn set_v6(&mut self, addr: [u8; 16], port: u16) {
+		self.v6 = Some(NetAddress::IPv6 { addr, port });
+	}
+	/// Sets the Tor Onion v2 socket address in this set, overwriting any previous Tor Onion v2
+	/// socket address.
+	pub fn set_onion_v2(&mut self, addr: [u8; 10], port: u16) {
+		self.onion2 = Some(NetAddress::OnionV2 { addr, port });
+	}
+	/// Sets the Tor Onion v3 socket address in this set, overwriting any previous Tor Onion v3
+	/// socket address.
+	pub fn set_onion_v3(&mut self, ed25519_pubkey: [u8; 32], checksum: u16, version: u8, port: u16) {
+		self.onion3 = Some(NetAddress::OnionV3 { ed25519_pubkey, checksum, version, port });
+	}
+
+	pub(crate) fn into_vec(mut self) -> Vec<NetAddress> {
+		let mut res = Vec::new();
+		if let Some(addr) = self.v4.take() {
+			res.push(addr);
+		}
+		if let Some(addr) = self.v6.take() {
+			res.push(addr);
+		}
+		if let Some(addr) = self.onion2.take() {
+			res.push(addr);
+		}
+		if let Some(addr) = self.onion3.take() {
+			res.push(addr);
+		}
+		res
+	}
+}
+
 impl Writeable for NetAddress {
 	fn write<W: Writer>(&self, writer: &mut W) -> Result<(), ::std::io::Error> {
 		match self {
-- 
2.39.5