Don't try to send oversized packets (#10042)

* Don't construct oversized packets

* Add test for payload limit

* [eth-sync] Fix wrongly computed data sizes

* Replace `MAX_RECEIPTS_TO_SEND` with overall softlimit

util/network-devp2p/src/connection.rs

@@ -41,6 +41,10 @@ const ENCRYPTED_HEADER_LEN: usize = 32;
 const RECEIVE_PAYLOAD: Duration = Duration::from_secs(30);
 pub const MAX_PAYLOAD_SIZE: usize = (1 << 24) - 1;
 
+/// Network responses should try not to go over this limit.
+/// This should be lower than MAX_PAYLOAD_SIZE
+pub const PAYLOAD_SOFT_LIMIT: usize = (1 << 22) - 1;
+
 pub trait GenericSocket : Read + Write {
 }
 

util/network-devp2p/src/host.rs

@@ -46,6 +46,7 @@ use ip_utils::{map_external_address, select_public_address};
 use parity_path::restrict_permissions_owner;
 use parking_lot::{Mutex, RwLock};
 use network::{ConnectionFilter, ConnectionDirection};
+use connection::PAYLOAD_SOFT_LIMIT;
 
 type Slab<T> = ::slab::Slab<T, usize>;
 
@@ -200,6 +201,10 @@ impl<'s> NetworkContextTrait for NetworkContext<'s> {
 			.map(|node| self.reserved_peers.contains(&node))
 			.unwrap_or(false)
 	}
+
+	fn payload_soft_limit(&self) -> usize {
+		PAYLOAD_SOFT_LIMIT
+	}
 }
 
 /// Shared host information

util/network/src/lib.rs

@@ -288,6 +288,9 @@ pub trait NetworkContext {
 
 	/// Returns whether the given peer ID is a reserved peer.
 	fn is_reserved_peer(&self, peer: PeerId) -> bool;
+
+	/// Returns the size the payload shouldn't exceed
+	fn payload_soft_limit(&self) -> usize;
 }
 
 impl<'a, T> NetworkContext for &'a T where T: ?Sized + NetworkContext {
@@ -338,6 +341,10 @@ impl<'a, T> NetworkContext for &'a T where T: ?Sized + NetworkContext {
 	fn is_reserved_peer(&self, peer: PeerId) -> bool {
 		(**self).is_reserved_peer(peer)
 	}
+
+	fn payload_soft_limit(&self) -> usize {
+		(**self).payload_soft_limit()
+	}
 }
 
 /// Network IO protocol handler. This needs to be implemented for each new subprotocol.