Add a flag for storing invalid blocks (sigp#4194)

NA

Adds a flag to store invalid blocks on disk for teh debugz. Only *some* invalid blocks are stored, those which:

- Were received via gossip (rather than RPC, for instance)
    - This keeps things simple to start with and should capture most blocks.
- Passed gossip verification
    - This reduces the ability for random people to fill up our disk. A proposer signature is required to write something to disk.

It's possible that we'll store blocks that aren't necessarily invalid, but we had an internal error during verification. Those blocks seem like they might be useful sometimes.

Author: paulhauner

beacon_node/lighthouse_network/src/config.rs

@@ -145,6 +145,9 @@ pub struct Config {
 
     /// Configuration for the outbound rate limiter (requests made by this node).
     pub outbound_rate_limiter_config: Option<OutboundRateLimiterConfig>,
+
+    /// Configures if/where invalid blocks should be stored.
+    pub invalid_block_storage: Option<PathBuf>,
 }
 
 impl Config {
@@ -329,6 +332,7 @@ impl Default for Config {
             metrics_enabled: false,
             enable_light_client_server: false,
             outbound_rate_limiter_config: None,
+            invalid_block_storage: None,
         }
     }
 }

beacon_node/network/src/beacon_processor/tests.rs

@@ -203,6 +203,7 @@ impl TestRig {
             max_workers: cmp::max(1, num_cpus::get()),
             current_workers: 0,
             importing_blocks: duplicate_cache.clone(),
+            invalid_block_storage: InvalidBlockStorage::Disabled,
             log: log.clone(),
         }
         .spawn_manager(beacon_processor_rx, Some(work_journal_tx));

beacon_node/network/src/router.rs

@@ -6,7 +6,7 @@
 #![allow(clippy::unit_arg)]
 
 use crate::beacon_processor::{
-    BeaconProcessor, WorkEvent as BeaconWorkEvent, MAX_WORK_EVENT_QUEUE_LEN,
+    BeaconProcessor, InvalidBlockStorage, WorkEvent as BeaconWorkEvent, MAX_WORK_EVENT_QUEUE_LEN,
 };
 use crate::error;
 use crate::service::{NetworkMessage, RequestId};
@@ -80,6 +80,7 @@ impl<T: BeaconChainTypes> Router<T> {
         network_globals: Arc<NetworkGlobals<T::EthSpec>>,
         network_send: mpsc::UnboundedSender<NetworkMessage<T::EthSpec>>,
         executor: task_executor::TaskExecutor,
+        invalid_block_storage: InvalidBlockStorage,
         log: slog::Logger,
     ) -> error::Result<mpsc::UnboundedSender<RouterMessage<T::EthSpec>>> {
         let message_handler_log = log.new(o!("service"=> "router"));
@@ -111,6 +112,7 @@ impl<T: BeaconChainTypes> Router<T> {
             max_workers: cmp::max(1, num_cpus::get()),
             current_workers: 0,
             importing_blocks: Default::default(),
+            invalid_block_storage,
             log: log.clone(),
         }
         .spawn_manager(beacon_processor_receive, None);

beacon_node/network/src/service.rs

@@ -1,4 +1,5 @@
 use super::sync::manager::RequestId as SyncId;
+use crate::beacon_processor::InvalidBlockStorage;
 use crate::persisted_dht::{clear_dht, load_dht, persist_dht};
 use crate::router::{Router, RouterMessage};
 use crate::subnet_service::SyncCommitteeService;
@@ -295,6 +296,12 @@ impl<T: BeaconChainTypes> NetworkService<T> {
             }
         }
 
+        let invalid_block_storage = config
+            .invalid_block_storage
+            .clone()
+            .map(InvalidBlockStorage::Enabled)
+            .unwrap_or(InvalidBlockStorage::Disabled);
+
         // launch derived network services
 
         // router task
@@ -303,6 +310,7 @@ impl<T: BeaconChainTypes> NetworkService<T> {
             network_globals.clone(),
             network_senders.network_send(),
             executor.clone(),
+            invalid_block_storage,
             network_log.clone(),
         )?;
 

beacon_node/src/cli.rs

@@ -1135,4 +1135,13 @@ pub fn cli_app<'a, 'b>() -> App<'a, 'b> {
             // always using the builder.
             .conflicts_with("builder-profit-threshold")
         )
+        .arg(
+            Arg::with_name("invalid-gossip-verified-blocks-path")
+            .long("invalid-gossip-verified-blocks-path")
+            .value_name("PATH")
+            .help("If a block succeeds gossip validation whilst failing full validation, store \
+                    the block SSZ as a file at this path. This feature is only recommended for \
+                    developers. This directory is not pruned, users should be careful to avoid \
+                    filling up their disks.")
+        )
 }

beacon_node/src/config.rs

@@ -830,6 +830,11 @@ pub fn get_config<E: EthSpec>(
     client_config.chain.enable_backfill_rate_limiting =
         !cli_args.is_present("disable-backfill-rate-limiting");
 
+    if let Some(path) = clap_utils::parse_optional(cli_args, "invalid-gossip-verified-blocks-path")?
+    {
+        client_config.network.invalid_block_storage = Some(path);
+    }
+
     Ok(client_config)
 }
 

lighthouse/tests/beacon_node.rs

@@ -2238,3 +2238,24 @@ fn disable_optimistic_finalized_sync() {
             assert!(!config.chain.optimistic_finalized_sync);
         });
 }
+
+#[test]
+fn invalid_gossip_verified_blocks_path_default() {
+    CommandLineTest::new()
+        .run_with_zero_port()
+        .with_config(|config| assert_eq!(config.network.invalid_block_storage, None));
+}
+
+#[test]
+fn invalid_gossip_verified_blocks_path() {
+    let path = "/home/karlm/naughty-blocks";
+    CommandLineTest::new()
+        .flag("invalid-gossip-verified-blocks-path", Some(path))
+        .run_with_zero_port()
+        .with_config(|config| {
+            assert_eq!(
+                config.network.invalid_block_storage,
+                Some(PathBuf::from(path))
+            )
+        });
+}