[network] Add testing for connection limits

Closes: aptos-labs#8474

config/management/operational/src/test_helper.rs

@@ -9,7 +9,7 @@ use crate::{
     validator_set::DecryptedValidatorInfo,
     TransactionContext,
 };
-use diem_config::{config, config::Peer};
+use diem_config::{config, config::Peer, network_id::NetworkId};
 use diem_crypto::{ed25519::Ed25519PublicKey, x25519};
 use diem_management::{error::Error, secure_backend::DISK};
 use diem_types::{
@@ -62,14 +62,22 @@ impl OperationalTool {
         command.account_resource()
     }
 
-    pub fn check_endpoint(&self, network_address: NetworkAddress) -> Result<String, Error> {
+    pub fn check_endpoint(
+        &self,
+        network_id: NetworkId,
+        network_address: NetworkAddress,
+    ) -> Result<String, Error> {
         let args = format!(
             "
                 {command}
                 --address {network_address}
+                --chain-id {chain_id}
+                --network-id {network_id}
             ",
             command = command(TOOL_NAME, CommandName::CheckEndpoint),
+            chain_id = self.chain_id.id(),
             network_address = network_address,
+            network_id = network_id
         );
         let command = Command::from_iter(args.split_whitespace());
         command.check_endpoint()

testsuite/diem-swarm/src/swarm.rs

@@ -10,7 +10,11 @@ use diem_genesis_tool::{
 };
 use diem_logger::prelude::*;
 use diem_temppath::TempPath;
-use diem_types::{account_address::AccountAddress, PeerId};
+use diem_types::{
+    account_address::AccountAddress,
+    network_address::{NetworkAddress, Protocol},
+    PeerId,
+};
 use std::{
     collections::HashMap,
     env,
@@ -326,6 +330,33 @@ impl DiemNode {
             }
         }
     }
+
+    pub fn public_address(&self) -> NetworkAddress {
+        let network = self
+            .config
+            .full_node_networks
+            .iter()
+            .find(|network| network.network_id == NetworkId::Public)
+            .unwrap();
+        let port = network
+            .listen_address
+            .as_slice()
+            .iter()
+            .find_map(|proto| {
+                if let Protocol::Tcp(port) = proto {
+                    Some(port)
+                } else {
+                    None
+                }
+            })
+            .unwrap();
+        let key = network.identity_key().public_key();
+        NetworkAddress::from_str(&format!(
+            "/ip4/126.0.0.1/tcp/{}/ln-noise-ik/{}/ln-handshake/0",
+            port, key
+        ))
+        .unwrap()
+    }
 }
 
 pub enum HealthStatus {

testsuite/smoke-test/src/full_nodes.rs

@@ -5,15 +5,15 @@ use crate::{smoke_test_environment::SmokeTestEnvironment, test_utils::compare_ba
 use cli::client_proxy::{ClientProxy, IndexAndSequence};
 use diem_client::AccountAddress;
 use diem_config::{
-    config::{NodeConfig, Peer, PeerRole, HANDSHAKE_VERSION},
+    config::{DiscoveryMethod, NodeConfig, Peer, PeerRole, HANDSHAKE_VERSION},
     network_id::NetworkId,
 };
+use diem_operational_tool::test_helper::OperationalTool;
 use diem_types::{
     account_config::{testnet_dd_account_address, treasury_compliance_account_address},
     network_address::{NetworkAddress, Protocol},
 };
 use std::{collections::HashSet, net::Ipv4Addr};
-use diem_config::config::DiscoveryMethod;
 
 // TODO: All of this convenience code below should be put in the client proxy directly, it's
 // very hard for users to know what the order of a bunch of random inputs should be
@@ -378,6 +378,14 @@ fn test_private_full_node() {
         vec![(10.0, XUS.to_string())],
         get_balances(&mut validator_client, 0),
     ));
+
+    // Check that we can't connect, testing the connection limit
+    let op_tool = OperationalTool::test();
+    let mut private_swarm = private_swarm.lock();
+    let private_node = private_swarm.mut_node(0).unwrap();
+    op_tool
+        .check_endpoint(NetworkId::Public, private_node.public_address())
+        .expect_err("Shouldn't be able to connect to private node anonymously");
 }
 
 fn add_node_to_seeds(