Add a helper struct to allow a user to safely pass in an addr list

diff --git a/lightning/src/ln/msgs.rs b/lightning/src/ln/msgs.rs
index d4d09dc2ae0ef9ef1beb1c208d369795defb5c59..03a2917802d370b014860b319f03a02cde855127 100644 (file)
--- a/lightning/src/ln/msgs.rs
+++ b/lightning/src/ln/msgs.rs
@@ -305,6 +305,58 @@ 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 addresses
+       /// (if any).
+       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 IPv4 socket addresses
+       /// (if any).
+       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 IPv4 socket
+       /// address (if any).
+       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 IPv4 socket
+       /// address (if any).
+       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 to_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 {