Support IPv6 in BN and VC HTTP APIs (#3104)

## Issue Addressed

#3103

## Proposed Changes

Parse `http-address` and `metrics-address` as `IpAddr` for both the beacon node and validator client to support IPv6 addresses.
Also adjusts parsing of CORS origins to allow for IPv6 addresses.

## Usage
You can now set  `http-address` and/or `metrics-address`  flags to IPv6 addresses.
For example, the following:
`lighthouse bn --http --http-address :: --metrics --metrics-address ::1`
will expose the beacon node HTTP server on `[::]` (equivalent of `0.0.0.0` in IPv4) and the metrics HTTP server on `localhost` (the equivalent of `127.0.0.1` in IPv4) 

The beacon node API can then be accessed by:
`curl "http://[server-ipv6-address]:5052/eth/v1/some_endpoint"`

And the metrics server api can be accessed by:
`curl "http://localhost:5054/metrics"` or by `curl "http://[::1]:5054/metrics"`

## Additional Info
On most Linux distributions the `v6only` flag is set to `false` by default (see the section for the `IPV6_V6ONLY` flag in https://www.man7.org/linux/man-pages/man7/ipv6.7.html) which means IPv4 connections will continue to function on a IPv6 address (providing it is appropriately mapped). This means that even if the Lighthouse API is running on `::` it is also possible to accept IPv4 connections.

However on Windows, this is not the case. The `v6only` flag is set to `true` so binding to `::` will only allow IPv6 connections.

beacon_node/http_api/src/lib.rs

@@ -38,7 +38,7 @@ use state_id::StateId;
 use std::borrow::Cow;
 use std::convert::TryInto;
 use std::future::Future;
-use std::net::{Ipv4Addr, SocketAddr, SocketAddrV4};
+use std::net::{IpAddr, Ipv4Addr, SocketAddr};
 use std::path::PathBuf;
 use std::pin::Pin;
 use std::sync::Arc;
@@ -98,7 +98,7 @@ pub struct Context<T: BeaconChainTypes> {
 #[derive(PartialEq, Debug, Clone, Serialize, Deserialize)]
 pub struct Config {
     pub enabled: bool,
-    pub listen_addr: Ipv4Addr,
+    pub listen_addr: IpAddr,
     pub listen_port: u16,
     pub allow_origin: Option<String>,
     pub serve_legacy_spec: bool,
@@ -110,7 +110,7 @@ impl Default for Config {
     fn default() -> Self {
         Self {
             enabled: false,
-            listen_addr: Ipv4Addr::new(127, 0, 0, 1),
+            listen_addr: IpAddr::V4(Ipv4Addr::new(127, 0, 0, 1)),
             listen_port: 5052,
             allow_origin: None,
             serve_legacy_spec: true,
@@ -2790,7 +2790,7 @@ pub fn serve<T: BeaconChainTypes>(
         .map(|reply| warp::reply::with_header(reply, "Server", &version_with_platform()))
         .with(cors_builder.build());
 
-    let http_socket: SocketAddrV4 = SocketAddrV4::new(config.listen_addr, config.listen_port);
+    let http_socket: SocketAddr = SocketAddr::new(config.listen_addr, config.listen_port);
     let http_server: HttpServer = match config.tls_config {
         Some(tls_config) => {
             let (socket, server) = warp::serve(routes)

beacon_node/http_api/tests/common.rs

@@ -15,7 +15,7 @@ use network::NetworkMessage;
 use sensitive_url::SensitiveUrl;
 use slog::Logger;
 use std::future::Future;
-use std::net::{Ipv4Addr, SocketAddr};
+use std::net::{IpAddr, Ipv4Addr, SocketAddr};
 use std::sync::Arc;
 use std::time::Duration;
 use tokio::sync::{mpsc, oneshot};
@@ -128,7 +128,7 @@ pub async fn create_api_server<T: BeaconChainTypes>(
     let context = Arc::new(Context {
         config: Config {
             enabled: true,
-            listen_addr: Ipv4Addr::new(127, 0, 0, 1),
+            listen_addr: IpAddr::V4(Ipv4Addr::new(127, 0, 0, 1)),
             listen_port: 0,
             allow_origin: None,
             serve_legacy_spec: true,

beacon_node/http_metrics/src/lib.rs

@@ -9,7 +9,7 @@ use lighthouse_version::version_with_platform;
 use serde::{Deserialize, Serialize};
 use slog::{crit, info, Logger};
 use std::future::Future;
-use std::net::{Ipv4Addr, SocketAddr, SocketAddrV4};
+use std::net::{IpAddr, Ipv4Addr, SocketAddr};
 use std::path::PathBuf;
 use std::sync::Arc;
 use warp::{http::Response, Filter};
@@ -48,7 +48,7 @@ pub struct Context<T: BeaconChainTypes> {
 #[derive(PartialEq, Debug, Clone, Serialize, Deserialize)]
 pub struct Config {
     pub enabled: bool,
-    pub listen_addr: Ipv4Addr,
+    pub listen_addr: IpAddr,
     pub listen_port: u16,
     pub allow_origin: Option<String>,
     pub allocator_metrics_enabled: bool,
@@ -58,7 +58,7 @@ impl Default for Config {
     fn default() -> Self {
         Self {
             enabled: false,
-            listen_addr: Ipv4Addr::new(127, 0, 0, 1),
+            listen_addr: IpAddr::V4(Ipv4Addr::new(127, 0, 0, 1)),
             listen_port: 5054,
             allow_origin: None,
             allocator_metrics_enabled: true,
@@ -131,7 +131,7 @@ pub fn serve<T: BeaconChainTypes>(
         .with(cors_builder.build());
 
     let (listening_socket, server) = warp::serve(routes).try_bind_with_graceful_shutdown(
-        SocketAddrV4::new(config.listen_addr, config.listen_port),
+        SocketAddr::new(config.listen_addr, config.listen_port),
         async {
             shutdown.await;
         },

beacon_node/http_metrics/tests/tests.rs

@@ -2,7 +2,7 @@ use beacon_chain::test_utils::EphemeralHarnessType;
 use environment::null_logger;
 use http_metrics::Config;
 use reqwest::StatusCode;
-use std::net::Ipv4Addr;
+use std::net::{IpAddr, Ipv4Addr};
 use std::sync::Arc;
 use tokio::sync::oneshot;
 use types::MainnetEthSpec;
@@ -17,7 +17,7 @@ async fn returns_200_ok() {
         let context = Arc::new(Context {
             config: Config {
                 enabled: true,
-                listen_addr: Ipv4Addr::new(127, 0, 0, 1),
+                listen_addr: IpAddr::V4(Ipv4Addr::new(127, 0, 0, 1)),
                 listen_port: 0,
                 allow_origin: None,
                 allocator_metrics_enabled: true,

beacon_node/src/config.rs

@@ -93,8 +93,8 @@ pub fn get_config<E: EthSpec>(
 
     if let Some(address) = cli_args.value_of("http-address") {
         client_config.http_api.listen_addr = address
-            .parse::<Ipv4Addr>()
-            .map_err(|_| "http-address is not a valid IPv4 address.")?;
+            .parse::<IpAddr>()
+            .map_err(|_| "http-address is not a valid IP address.")?;
     }
 
     if let Some(port) = cli_args.value_of("http-port") {
@@ -145,8 +145,8 @@ pub fn get_config<E: EthSpec>(
 
     if let Some(address) = cli_args.value_of("metrics-address") {
         client_config.http_metrics.listen_addr = address
-            .parse::<Ipv4Addr>()
-            .map_err(|_| "metrics-address is not a valid IPv4 address.")?;
+            .parse::<IpAddr>()
+            .map_err(|_| "metrics-address is not a valid IP address.")?;
     }
 
     if let Some(port) = cli_args.value_of("metrics-port") {