From 44b4970ad8238aaf4b95309132d4c138abc304c7 Mon Sep 17 00:00:00 2001
From: Richard Watts <richard@zilliqa.com>
Date: Tue, 26 Nov 2024 08:45:34 +0000
Subject: [PATCH] (feat) Ignore status where necessary - some chains don't
 provide it

---
 bridge-validators/config.toml   |  5 +++++
 bridge-validators/src/block.rs  | 11 ++++++++---
 bridge-validators/src/client.rs |  5 ++++-
 bridge-validators/src/main.rs   |  5 +++++
 4 files changed, 22 insertions(+), 4 deletions(-)

diff --git a/bridge-validators/config.toml b/bridge-validators/config.toml
index 5a7e990..fa3f4ef 100644
--- a/bridge-validators/config.toml
+++ b/bridge-validators/config.toml
@@ -42,6 +42,11 @@ legacy_gas_estimation_percent = 130
 ## fetching the receipt and scanning it for relevant logs. This is slow, but at least it works ..
 ## use_get_transactions = true
 
+## Some chains (like ZQ1) insist on generating events for failed txns; these come with a status==0
+## value. However, other chains (eg. BSC) do not send a status==0 value but only generate events
+## for txns which succeed. In order to fail safe, we need to mark when we should accept logs with
+## nonexistent statuses
+accept_events_with_no_status = true
 
 # BSC Mainnet
 # [[chain_configs]]
diff --git a/bridge-validators/src/block.rs b/bridge-validators/src/block.rs
index c98f710..01b2211 100644
--- a/bridge-validators/src/block.rs
+++ b/bridge-validators/src/block.rs
@@ -65,8 +65,10 @@ impl ChainClient {
                                 info!("[1] txn failed - skipping");
                                 continue;
                             }
+                        } else if self.accept_events_with_no_status {
+                            info!("[1] txn {:#x} has no status - accept_events_with_no_status = true; accepting", txn_hash);
                         } else {
-                            info!("[1] txn {:#x} has no status - ignoring", txn_hash);
+                            info!("[1] txn {:#x} has no status - accept_events_with_no_status = false; rejecting", txn_hash);
                             continue;
                         }
                         info!("Got receipt for txn {:#x}", txn_hash);
@@ -168,7 +170,8 @@ impl BlockPolling for ChainClient {
                     .filter(|log| {
                         log.get("status")
                             .and_then(|v| v.as_i64())
-                            .map_or(false, |s| {
+                            .map_or(
+                                self.accept_events_with_no_status, |s| {
                                 if s != 1 {
                                     info!("txn failed: status = {s:#x}");
                                     false
@@ -183,10 +186,12 @@ impl BlockPolling for ChainClient {
                             .and_then(|val| val.parse::<Address>().ok())
                             .map(|from_address| {
                                 if from_address == self.chain_gateway_address {
+                                    info!("event from {0:#x} has correct chain_gateway_address {1:#x}; accepting",
+                                          from_address, self.chain_gateway_address);
                                     true
                                 } else {
                                     info!(
-                                        "event from {0:#x} , chain gateway {1:#x}",
+                                        "event from {0:#x} , chain gateway {1:#x} - rejecting",
                                         from_address, self.chain_gateway_address
                                     );
                                     false
diff --git a/bridge-validators/src/client.rs b/bridge-validators/src/client.rs
index 8af79d2..f4bd915 100644
--- a/bridge-validators/src/client.rs
+++ b/bridge-validators/src/client.rs
@@ -36,6 +36,7 @@ pub struct ChainClient {
     pub scan_behind_blocks: u64,
     pub log_strategy: LogStrategy,
     pub to_block_number: Option<u64>,
+    pub accept_events_with_no_status: bool,
 }
 
 impl fmt::Display for ChainClient {
@@ -46,8 +47,9 @@ impl fmt::Display for ChainClient {
 
 impl ChainClient {
     pub async fn new(config: &ChainConfig, wallet: LocalWallet) -> Result<Self> {
+        let accept_events_with_no_status = config.accept_events_with_no_status.unwrap_or(false);
         info!(
-            "initialising chain client for URL {0} with gateway {1:#x} ... ",
+            "initialising chain client for URL {0} with gateway {1:#x}; accept_events_with_no_status = {accept_events_with_no_status} ... ",
             config.rpc_url.as_str(),
             config.chain_gateway_address
         );
@@ -82,6 +84,7 @@ impl ChainClient {
             scan_behind_blocks: config.scan_behind_blocks.unwrap_or_default(),
             log_strategy: strategy,
             to_block_number: config.to_block_number,
+            accept_events_with_no_status,
         })
     }
 }
diff --git a/bridge-validators/src/main.rs b/bridge-validators/src/main.rs
index 00dfc7b..39a9721 100644
--- a/bridge-validators/src/main.rs
+++ b/bridge-validators/src/main.rs
@@ -35,6 +35,11 @@ pub struct ChainConfig {
     pub scan_behind_blocks: Option<u64>,
     pub use_get_transactions: Option<bool>,
     pub to_block_number: Option<u64>,
+    /// If set, we will accept events with no status - this covers the vast
+    /// majority of networks; Zilliqa 1 unfortunely will emit events with no
+    /// status, and failing safe requires us to generate the option this way
+    /// around :-(
+    pub accept_events_with_no_status: Option<bool>,
 }
 
 #[derive(Debug, Clone, Deserialize)]