Update discv5 to expand ipv6 support (#4319)

Done in different PRs so that they can reviewed independently, as it's likely this won't be merged before I leave

Includes resolution for #4080 
- [ ] #4299
- [ ] #4318
- [ ] #4320 

Co-authored-by: Diva M <divma@protonmail.com>
Co-authored-by: Age Manning <Age@AgeManning.com>

boot_node/src/config.rs

@@ -2,7 +2,6 @@ use beacon_node::{get_data_dir, set_network_config};
 use clap::ArgMatches;
 use eth2_network_config::Eth2NetworkConfig;
 use lighthouse_network::discovery::create_enr_builder_from_config;
-use lighthouse_network::discv5::IpMode;
 use lighthouse_network::discv5::{enr::CombinedKey, Discv5Config, Enr};
 use lighthouse_network::{
     discovery::{load_enr_from_disk, use_or_load_enr},
@@ -10,13 +9,12 @@ use lighthouse_network::{
 };
 use serde_derive::{Deserialize, Serialize};
 use ssz::Encode;
-use std::net::SocketAddr;
+use std::net::{SocketAddrV4, SocketAddrV6};
 use std::{marker::PhantomData, path::PathBuf};
 use types::EthSpec;
 
 /// A set of configuration parameters for the bootnode, established from CLI arguments.
 pub struct BootNodeConfig<T: EthSpec> {
-    pub listen_socket: SocketAddr,
     // TODO: Generalise to multiaddr
     pub boot_nodes: Vec<Enr>,
     pub local_enr: Enr,
@@ -81,31 +79,6 @@ impl<T: EthSpec> BootNodeConfig<T> {
             network_config.discv5_config.enr_update = false;
         }
 
-        // the address to listen on
-        let listen_socket = match network_config.listen_addrs().clone() {
-            lighthouse_network::ListenAddress::V4(v4_addr) => {
-                // Set explicitly as ipv4 otherwise
-                network_config.discv5_config.ip_mode = IpMode::Ip4;
-                v4_addr.udp_socket_addr()
-            }
-            lighthouse_network::ListenAddress::V6(v6_addr) => {
-                // create ipv6 sockets and enable ipv4 mapped addresses.
-                network_config.discv5_config.ip_mode = IpMode::Ip6 {
-                    enable_mapped_addresses: false,
-                };
-
-                v6_addr.udp_socket_addr()
-            }
-            lighthouse_network::ListenAddress::DualStack(_v4_addr, v6_addr) => {
-                // create ipv6 sockets and enable ipv4 mapped addresses.
-                network_config.discv5_config.ip_mode = IpMode::Ip6 {
-                    enable_mapped_addresses: true,
-                };
-
-                v6_addr.udp_socket_addr()
-            }
-        };
-
         let private_key = load_private_key(&network_config, &logger);
         let local_key = CombinedKey::from_libp2p(&private_key)?;
 
@@ -143,7 +116,7 @@ impl<T: EthSpec> BootNodeConfig<T> {
                 let mut builder = create_enr_builder_from_config(&network_config, enable_tcp);
                 // If we know of the ENR field, add it to the initial construction
                 if let Some(enr_fork_bytes) = enr_fork {
-                    builder.add_value("eth2", enr_fork_bytes.as_slice());
+                    builder.add_value("eth2", &enr_fork_bytes);
                 }
                 builder
                     .build(&local_key)
@@ -155,7 +128,6 @@ impl<T: EthSpec> BootNodeConfig<T> {
         };
 
         Ok(BootNodeConfig {
-            listen_socket,
             boot_nodes,
             local_enr,
             local_key,
@@ -170,7 +142,8 @@ impl<T: EthSpec> BootNodeConfig<T> {
 /// Its fields are a subset of the fields of `BootNodeConfig`, some of them are copied from `Discv5Config`.
 #[derive(Serialize, Deserialize)]
 pub struct BootNodeConfigSerialization {
-    pub listen_socket: SocketAddr,
+    pub ipv4_listen_socket: Option<SocketAddrV4>,
+    pub ipv6_listen_socket: Option<SocketAddrV6>,
     // TODO: Generalise to multiaddr
     pub boot_nodes: Vec<Enr>,
     pub local_enr: Enr,
@@ -183,7 +156,6 @@ impl BootNodeConfigSerialization {
     /// relevant fields of `config`
     pub fn from_config_ref<T: EthSpec>(config: &BootNodeConfig<T>) -> Self {
         let BootNodeConfig {
-            listen_socket,
             boot_nodes,
             local_enr,
             local_key: _,
@@ -191,8 +163,27 @@ impl BootNodeConfigSerialization {
             phantom: _,
         } = config;
 
+        let (ipv4_listen_socket, ipv6_listen_socket) = match discv5_config.listen_config {
+            lighthouse_network::discv5::ListenConfig::Ipv4 { ip, port } => {
+                (Some(SocketAddrV4::new(ip, port)), None)
+            }
+            lighthouse_network::discv5::ListenConfig::Ipv6 { ip, port } => {
+                (None, Some(SocketAddrV6::new(ip, port, 0, 0)))
+            }
+            lighthouse_network::discv5::ListenConfig::DualStack {
+                ipv4,
+                ipv4_port,
+                ipv6,
+                ipv6_port,
+            } => (
+                Some(SocketAddrV4::new(ipv4, ipv4_port)),
+                Some(SocketAddrV6::new(ipv6, ipv6_port, 0, 0)),
+            ),
+        };
+
         BootNodeConfigSerialization {
-            listen_socket: *listen_socket,
+            ipv4_listen_socket,
+            ipv6_listen_socket,
             boot_nodes: boot_nodes.clone(),
             local_enr: local_enr.clone(),
             disable_packet_filter: !discv5_config.enable_packet_filter,