From ff4d68d2be12b2b1b5f153d7c6c8d1f796df2c1d Mon Sep 17 00:00:00 2001
From: Antioch Peverell <30642645+antiochp@users.noreply.github.com>
Date: Wed, 21 Mar 2018 16:50:08 -0400
Subject: [PATCH] config to enable full chain validation per block (#839)

* default to full chain validation on processing each block (except during sync)
* add sample config for chain_validation_mode
* document chain_validation_mode
---
 grin.toml            |  6 ++++++
 grin/src/adapters.rs | 36 +++++++++++++++++++++++++++++++++++-
 grin/src/server.rs   |  1 +
 grin/src/types.rs    | 21 +++++++++++++++++++++
 4 files changed, 63 insertions(+), 1 deletion(-)

diff --git a/grin.toml b/grin.toml
index ef7c21907..1ef71c397 100644
--- a/grin.toml
+++ b/grin.toml
@@ -42,6 +42,12 @@ db_root = ".grin"
 #
 chain_type = "Testnet2"
 
+#The chain validation mode, defines how often (if at all) we
+#want to run a full chain validation. Can be:
+#EveryBlock - run full chain validation when processing each block (except during sync)
+#Disabled - disable full chain validation (just run regular block validation)
+#chain_validation_mode=EveryBlock
+
 #run the node in "full archive" mode (default is fast-sync, pruned node)
 #archive_mode = false
 
diff --git a/grin/src/adapters.rs b/grin/src/adapters.rs
index d93cc5231..74be3e1c9 100644
--- a/grin/src/adapters.rs
+++ b/grin/src/adapters.rs
@@ -17,6 +17,7 @@ use std::net::SocketAddr;
 use std::ops::Deref;
 use std::sync::{Arc, RwLock, Weak};
 use std::sync::atomic::{AtomicBool, Ordering};
+use std::time::Instant;
 use rand;
 use rand::Rng;
 
@@ -30,6 +31,7 @@ use p2p;
 use pool;
 use util::OneTime;
 use store;
+use types::{ChainValidationMode, ServerConfig};
 use util::LOGGER;
 
 // All adapters use `Weak` references instead of `Arc` to avoid cycles that
@@ -51,6 +53,7 @@ pub struct NetToChainAdapter {
 	chain: Weak<chain::Chain>,
 	tx_pool: Arc<RwLock<pool::TransactionPool<PoolToChainAdapter>>>,
 	peers: OneTime<Weak<p2p::Peers>>,
+	config: ServerConfig,
 }
 
 impl p2p::ChainAdapter for NetToChainAdapter {
@@ -334,12 +337,14 @@ impl NetToChainAdapter {
 		currently_syncing: Arc<AtomicBool>,
 		chain_ref: Weak<chain::Chain>,
 		tx_pool: Arc<RwLock<pool::TransactionPool<PoolToChainAdapter>>>,
+		config: ServerConfig,
 	) -> NetToChainAdapter {
 		NetToChainAdapter {
 			currently_syncing: currently_syncing,
 			chain: chain_ref,
 			tx_pool: tx_pool,
 			peers: OneTime::new(),
+			config: config,
 		}
 	}
 
@@ -388,7 +393,7 @@ impl NetToChainAdapter {
 		let prev_hash = b.header.previous;
 		let bhash = b.hash();
 		let chain = w(&self.chain);
-		match chain.process_block(b, self.chain_opts()) {
+		let result = match chain.process_block(b, self.chain_opts()) {
 			Ok(_) => true,
 			Err(chain::Error::Orphan) => {
 				// make sure we did not miss the parent block
@@ -415,7 +420,36 @@ impl NetToChainAdapter {
 				);
 				true
 			}
+		};
+
+		// If we are running in "validate the full chain every block" then
+		// panic here if validation fails for any reason.
+		// We are out of consensus at this point and want to track the problem
+		// down as soon as possible.
+		// Skip this if we are currently syncing (too slow).
+		if !self.currently_syncing.load(Ordering::Relaxed)
+			&& self.config.chain_validation_mode == ChainValidationMode::EveryBlock
+		{
+			let now = Instant::now();
+
+			debug!(
+				LOGGER,
+				"adapter: process_block: ***** validating full chain state at {}", bhash,
+			);
+
+			let chain = w(&self.chain);
+			chain
+				.validate(true)
+				.expect("chain validation failed, hard stop");
+
+			debug!(
+				LOGGER,
+				"adapter: process_block: ***** done validating full chain state, took {}s",
+				now.elapsed().as_secs(),
+			);
 		}
+
+		result
 	}
 
 	// After receiving a compact block if we cannot successfully hydrate
diff --git a/grin/src/server.rs b/grin/src/server.rs
index ce48fad31..ce743e877 100644
--- a/grin/src/server.rs
+++ b/grin/src/server.rs
@@ -120,6 +120,7 @@ impl Server {
 			currently_syncing.clone(),
 			Arc::downgrade(&shared_chain),
 			tx_pool.clone(),
+			config.clone(),
 		));
 
 		let p2p_config = config.p2p_config.clone();
diff --git a/grin/src/types.rs b/grin/src/types.rs
index 7e77c52ea..4d980ede2 100644
--- a/grin/src/types.rs
+++ b/grin/src/types.rs
@@ -86,6 +86,22 @@ impl From<wallet::Error> for Error {
 	}
 }
 
+/// Type of seeding the server will use to find other peers on the network.
+#[derive(Debug, Clone, Serialize, Deserialize, PartialEq)]
+pub enum ChainValidationMode {
+	/// Run full chain validation after processing every block.
+	EveryBlock,
+	/// Do not automatically run chain validation during normal block
+	/// processing.
+	Disabled,
+}
+
+impl Default for ChainValidationMode {
+	fn default() -> ChainValidationMode {
+		ChainValidationMode::EveryBlock
+	}
+}
+
 /// Type of seeding the server will use to find other peers on the network.
 #[derive(Debug, Clone, Serialize, Deserialize, PartialEq)]
 pub enum Seeding {
@@ -122,6 +138,10 @@ pub struct ServerConfig {
 	/// Whether this node is a full archival node or a fast-sync, pruned node
 	pub archive_mode: Option<bool>,
 
+	/// Automatically run full chain validation during normal block processing?
+	#[serde(default)]
+	pub chain_validation_mode: ChainValidationMode,
+
 	/// Method used to get the list of seed nodes for initial bootstrap.
 	#[serde(default)]
 	pub seeding_type: Seeding,
@@ -169,6 +189,7 @@ impl Default for ServerConfig {
 			mining_config: Some(pow::types::MinerConfig::default()),
 			chain_type: ChainTypes::default(),
 			archive_mode: None,
+			chain_validation_mode: ChainValidationMode::default(),
 			pool_config: pool::PoolConfig::default(),
 			skip_sync_wait: None,
 			run_tui: None,