RPC: Add default and configurable response size limit to eth JSON-RPC server

lib/ain-cpp-imports/src/bridge.rs

@@ -35,6 +35,7 @@ pub mod ffi {
         fn getDatadir() -> String;
         fn getNetwork() -> String;
         fn getEthMaxConnections() -> u32;
+        fn getEthMaxResponseByteSize() -> u32;
         fn getDifficulty(block_hash: [u8; 32]) -> u32;
         fn getChainWork(block_hash: [u8; 32]) -> [u8; 32];
         fn getPoolTransactions() -> Vec<TransactionData>;

lib/ain-cpp-imports/src/lib.rs

@@ -47,6 +47,9 @@ mod ffi {
     pub fn getEthMaxConnections() -> u32 {
         unimplemented!("{}", UNIMPL_MSG)
     }
+    pub fn getEthMaxResponseByteSize() -> u32 {
+        unimplemented!("{}", UNIMPL_MSG)
+    }
     pub fn getNetwork() -> String {
         unimplemented!("{}", UNIMPL_MSG)
     }
@@ -146,6 +149,10 @@ pub fn get_max_connections() -> u32 {
     ffi::getEthMaxConnections()
 }
 
+pub fn get_max_response_byte_size() -> u32 {
+    ffi::getEthMaxResponseByteSize()
+}
+
 pub fn get_network() -> String {
     ffi::getNetwork()
 }

lib/ain-grpc/src/lib.rs

@@ -87,6 +87,7 @@ pub fn init_network_json_rpc_service(runtime: &Services, addr: &str) -> Result<(
     info!("Starting JSON RPC server at {}", addr);
     let addr = addr.parse::<SocketAddr>()?;
     let max_connections = ain_cpp_imports::get_max_connections();
+    let max_response_size = ain_cpp_imports::get_max_response_byte_size();
 
     let middleware = if !ain_cpp_imports::get_cors_allowed_origin().is_empty() {
         let origin = ain_cpp_imports::get_cors_allowed_origin();
@@ -107,6 +108,7 @@ pub fn init_network_json_rpc_service(runtime: &Services, addr: &str) -> Result<(
         ServerBuilder::default()
             .set_middleware(middleware)
             .max_connections(max_connections)
+            .max_response_body_size(max_response_size)
             .custom_tokio_runtime(handle)
             .build(addr),
     )?;
@@ -133,11 +135,13 @@ pub fn init_network_subscriptions_service(runtime: &Services, addr: &str) -> Res
     info!("Starting WebSockets server at {}", addr);
     let addr = addr.parse::<SocketAddr>()?;
     let max_connections = ain_cpp_imports::get_max_connections();
+    let max_response_size = ain_cpp_imports::get_max_response_byte_size();
 
     let handle = runtime.ws_rt_handle.clone();
     let server = runtime.ws_rt_handle.block_on(
         ServerBuilder::default()
             .max_subscriptions_per_connection(max_connections)
+            .max_response_body_size(max_response_size)
             .custom_tokio_runtime(handle)
             .set_id_provider(MetachainSubIdProvider)
             .build(addr),

src/ffi/ffiexports.cpp

@@ -308,6 +308,11 @@ uint32_t getEthMaxConnections() {
     return gArgs.GetArg("-ethmaxconnections", DEFAULT_ETH_MAX_CONNECTIONS);
 }
 
+uint32_t getEthMaxResponseByteSize() {
+    const auto max_response_size_mb = gArgs.GetArg("-ethmaxresponsesize", DEFAULT_ETH_MAX_RESPONSE_SIZE_MB);
+    return max_response_size_mb * 1024 * 1024;
+}
+
 rust::vec<DST20Token> getDST20Tokens(std::size_t mnview_ptr) {
     LOCK(cs_main);
 

src/ffi/ffiexports.h

@@ -10,7 +10,10 @@ static constexpr uint64_t DEFAULT_EVM_BLOCK_GAS_TARGET_FACTOR = 2;
 static constexpr uint64_t DEFAULT_EVM_BLOCK_GAS_LIMIT = 30000000;
 static constexpr uint64_t DEFAULT_EVM_FINALITY_COUNT = 100;
 static constexpr CAmount DEFAULT_EVM_RBF_FEE_INCREMENT = COIN / 10;
+
+// Defaults for attributes relating to networking
 static constexpr uint32_t DEFAULT_ETH_MAX_CONNECTIONS = 100;
+static constexpr uint32_t DEFAULT_ETH_MAX_RESPONSE_SIZE_MB = 25;  // 25 megabytes
 
 static constexpr uint32_t DEFAULT_ECC_LRU_CACHE_COUNT = 10000;
 static constexpr uint32_t DEFAULT_EVMV_LRU_CACHE_COUNT = 10000;
@@ -65,6 +68,7 @@ rust::string getDatadir();
 rust::string getNetwork();
 uint32_t getDifficulty(std::array<uint8_t, 32> blockHash);
 uint32_t getEthMaxConnections();
+uint32_t getEthMaxResponseByteSize();
 std::array<uint8_t, 32> getChainWork(std::array<uint8_t, 32> blockHash);
 rust::vec<TransactionData> getPoolTransactions();
 uint64_t getNativeTxSize(rust::Vec<uint8_t> rawTransaction);

src/init.cpp

@@ -655,6 +655,7 @@ void SetupServerArgs()
     gArgs.AddArg("-ethrpcport=<port>", strprintf("Listen for ETH-JSON-RPC connections on <port>> (default: %u, testnet: %u, changi: %u, devnet: %u, regtest: %u)", defaultBaseParams->ETHRPCPort(), testnetBaseParams->ETHRPCPort(), changiBaseParams->ETHRPCPort(), devnetBaseParams->ETHRPCPort(), regtestBaseParams->ETHRPCPort()), ArgsManager::ALLOW_ANY | ArgsManager::NETWORK_ONLY, OptionsCategory::RPC);
     gArgs.AddArg("-wsport=<port>", strprintf("Listen for ETH-WebSockets connections on <port>> (default: %u, testnet: %u, changi: %u, devnet: %u, regtest: %u)", defaultBaseParams->WSPort(), testnetBaseParams->WSPort(), changiBaseParams->WSPort(), devnetBaseParams->WSPort(), regtestBaseParams->ETHRPCPort()), ArgsManager::ALLOW_ANY | ArgsManager::NETWORK_ONLY, OptionsCategory::RPC);
     gArgs.AddArg("-ethmaxconnections=<connections>", strprintf("Set the maximum number of connections allowed by the ETH-RPC server (default: %u, testnet: %u, changi: %u, devnet: %u, regtest: %u)", DEFAULT_ETH_MAX_CONNECTIONS, DEFAULT_ETH_MAX_CONNECTIONS, DEFAULT_ETH_MAX_CONNECTIONS, DEFAULT_ETH_MAX_CONNECTIONS, DEFAULT_ETH_MAX_CONNECTIONS), ArgsManager::ALLOW_ANY | ArgsManager::NETWORK_ONLY, OptionsCategory::RPC);
+    gArgs.AddArg("-ethmaxresponsesize=<size>", strprintf("Set the maximum response size in MB by the ETH-RPC server (default: %u, testnet: %u, changi: %u, devnet: %u, regtest: %u)", DEFAULT_ETH_MAX_RESPONSE_SIZE_MB, DEFAULT_ETH_MAX_RESPONSE_SIZE_MB, DEFAULT_ETH_MAX_RESPONSE_SIZE_MB, DEFAULT_ETH_MAX_RESPONSE_SIZE_MB, DEFAULT_ETH_MAX_RESPONSE_SIZE_MB), ArgsManager::ALLOW_ANY | ArgsManager::NETWORK_ONLY, OptionsCategory::RPC);
     gArgs.AddArg("-ethdebug", strprintf("Enable debug_* ETH RPCs (default: %b)", DEFAULT_ETH_DEBUG_ENABLED), ArgsManager::ALLOW_ANY, OptionsCategory::RPC);
     gArgs.AddArg("-ethdebugtrace", strprintf("Enable debug_trace* ETH RPCs (default: %b)", DEFAULT_ETH_DEBUG_TRACE_ENABLED), ArgsManager::ALLOW_ANY, OptionsCategory::RPC);