From 77d0c065d349940854b8a2bf87430cc88ce715f7 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Tomasz=20Drwi=C4=99ga?= <tomusdrw@users.noreply.github.com>
Date: Wed, 27 Nov 2019 19:23:55 +0100
Subject: [PATCH] Hard-cap the execution time of custom contract calls. (#4226)
* Reject call requests that allocate too high gas limit.
* Lower to 5x
---
substrate/frame/contracts/rpc/src/lib.rs | 24 +++++++++++++++++++++++-
1 file changed, 23 insertions(+), 1 deletion(-)
diff --git a/substrate/frame/contracts/rpc/src/lib.rs b/substrate/frame/contracts/rpc/src/lib.rs
index e330e9efcc0..6f357f53b85 100644
--- a/substrate/frame/contracts/rpc/src/lib.rs
+++ b/substrate/frame/contracts/rpc/src/lib.rs
@@ -39,7 +39,16 @@ const RUNTIME_ERROR: i64 = 1;
const CONTRACT_DOESNT_EXIST: i64 = 2;
const CONTRACT_IS_A_TOMBSTONE: i64 = 3;
-// A private newtype for converting `GetStorageError` into an RPC error.
+/// A rough estimate of how much gas a decent hardware consumes per second,
+/// using native execution.
+/// This value is used to set the upper bound for maximal contract calls to
+/// prevent blocking the RPC for too long.
+///
+/// Based on W3F research spreadsheet:
+/// https://docs.google.com/spreadsheets/d/1h0RqncdqiWI4KgxO0z9JIpZEJESXjX_ZCK6LFX6veDo/view
+const GAS_PER_SECOND: u64 = 1_000_000_000;
+
+/// A private newtype for converting `GetStorageError` into an RPC error.
struct GetStorageError(runtime_api::GetStorageError);
impl From<GetStorageError> for Error {
fn from(e: GetStorageError) -> Error {
@@ -148,6 +157,19 @@ where
data: None,
})?;
+ let max_gas_limit = 5 * GAS_PER_SECOND;
+ if gas_limit > max_gas_limit {
+ return Err(Error {
+ code: ErrorCode::InvalidParams,
+ message: format!(
+ "Requested gas limit is greater than maximum allowed: {} > {}",
+ gas_limit,
+ max_gas_limit
+ ),
+ data: None,
+ });
+ }
+
let exec_result = api
.call(&at, origin, dest, value, gas_limit, input_data.to_vec())
.map_err(|e| Error {
--
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