fix(pbs): body default body size (#313)

Author: ltitanb

crates/pbs/src/constants.rs

@@ -10,9 +10,12 @@ pub const TIMEOUT_ERROR_CODE_STR: &str = "555";
 
 /// 20 MiB to cover edge cases for heavy blocks and also add a bit of slack for
 /// any Ethereum upgrades in the near future
-pub const MAX_SIZE_SUBMIT_BLOCK: usize = 20 * 1024 * 1024;
+pub const MAX_SIZE_SUBMIT_BLOCK_RESPONSE: usize = 20 * 1024 * 1024;
+
+/// 20 MiB, enough to process ~45000 registrations in one request
+pub const MAX_SIZE_REGISTER_VALIDATOR_REQUEST: usize = 20 * 1024 * 1024;
 
 /// 10 KiB, headers are around 700 bytes + buffer for encoding
-pub const MAX_SIZE_GET_HEADER: usize = 10 * 1024;
+pub const MAX_SIZE_GET_HEADER_RESPONSE: usize = 10 * 1024;
 
 pub const MAX_SIZE_DEFAULT: usize = 1024;

crates/pbs/src/mev_boost/get_header.rs

@@ -31,7 +31,8 @@ use url::Url;
 
 use crate::{
     constants::{
-        GET_HEADER_ENDPOINT_TAG, MAX_SIZE_GET_HEADER, TIMEOUT_ERROR_CODE, TIMEOUT_ERROR_CODE_STR,
+        GET_HEADER_ENDPOINT_TAG, MAX_SIZE_GET_HEADER_RESPONSE, TIMEOUT_ERROR_CODE,
+        TIMEOUT_ERROR_CODE_STR,
     },
     metrics::{RELAY_HEADER_VALUE, RELAY_LAST_SLOT, RELAY_LATENCY, RELAY_STATUS_CODE},
     state::{BuilderApiState, PbsState},
@@ -323,7 +324,7 @@ async fn send_one_get_header(
     let code = res.status();
     RELAY_STATUS_CODE.with_label_values(&[code.as_str(), GET_HEADER_ENDPOINT_TAG, &relay.id]).inc();
 
-    let response_bytes = read_chunked_body_with_max(res, MAX_SIZE_GET_HEADER).await?;
+    let response_bytes = read_chunked_body_with_max(res, MAX_SIZE_GET_HEADER_RESPONSE).await?;
     if !code.is_success() {
         return Err(PbsError::RelayResponse {
             error_msg: String::from_utf8_lossy(&response_bytes).into_owned(),

crates/pbs/src/mev_boost/submit_block.rs

@@ -16,7 +16,9 @@ use tracing::{debug, warn};
 use url::Url;
 
 use crate::{
-    constants::{MAX_SIZE_SUBMIT_BLOCK, SUBMIT_BLINDED_BLOCK_ENDPOINT_TAG, TIMEOUT_ERROR_CODE_STR},
+    constants::{
+        MAX_SIZE_SUBMIT_BLOCK_RESPONSE, SUBMIT_BLINDED_BLOCK_ENDPOINT_TAG, TIMEOUT_ERROR_CODE_STR,
+    },
     metrics::{RELAY_LATENCY, RELAY_STATUS_CODE},
     state::{BuilderApiState, PbsState},
     utils::read_chunked_body_with_max,
@@ -139,7 +141,7 @@ async fn send_submit_block(
         .with_label_values(&[code.as_str(), SUBMIT_BLINDED_BLOCK_ENDPOINT_TAG, &relay.id])
         .inc();
 
-    let response_bytes = read_chunked_body_with_max(res, MAX_SIZE_SUBMIT_BLOCK).await?;
+    let response_bytes = read_chunked_body_with_max(res, MAX_SIZE_SUBMIT_BLOCK_RESPONSE).await?;
     if !code.is_success() {
         let err = PbsError::RelayResponse {
             error_msg: String::from_utf8_lossy(&response_bytes).into_owned(),

crates/pbs/src/routes/router.rs

@@ -1,5 +1,5 @@
 use axum::{
-    extract::{MatchedPath, Request},
+    extract::{DefaultBodyLimit, MatchedPath, Request},
     middleware::{self, Next},
     response::Response,
     routing::{get, post},
@@ -20,16 +20,27 @@ use super::{
 use crate::{
     api::BuilderApi,
     state::{BuilderApiState, PbsStateGuard},
+    MAX_SIZE_REGISTER_VALIDATOR_REQUEST, MAX_SIZE_SUBMIT_BLOCK_RESPONSE,
 };
 
 pub fn create_app_router<S: BuilderApiState, A: BuilderApi<S>>(state: PbsStateGuard<S>) -> Router {
+    // DefaultBodyLimit is 2Mib by default, so we only increase it for a few routes
+    // thay may need more
+
     let builder_routes = Router::new()
         .route(GET_HEADER_PATH, get(handle_get_header::<S, A>))
         .route(GET_STATUS_PATH, get(handle_get_status::<S, A>))
-        .route(REGISTER_VALIDATOR_PATH, post(handle_register_validator::<S, A>))
-        .route(SUBMIT_BLOCK_PATH, post(handle_submit_block::<S, A>));
+        .route(
+            REGISTER_VALIDATOR_PATH,
+            post(handle_register_validator::<S, A>)
+                .route_layer(DefaultBodyLimit::max(MAX_SIZE_REGISTER_VALIDATOR_REQUEST)),
+        )
+        .route(
+            SUBMIT_BLOCK_PATH,
+            post(handle_submit_block::<S, A>)
+                .route_layer(DefaultBodyLimit::max(MAX_SIZE_SUBMIT_BLOCK_RESPONSE)),
+        ); // header is smaller than the response but err on the safe side
     let reload_router = Router::new().route(RELOAD_PATH, post(handle_reload::<S, A>));
-
     let builder_api = Router::new().nest(BUILDER_API_PATH, builder_routes).merge(reload_router);
 
     let app = if let Some(extra_routes) = A::extra_routes() {
@@ -58,7 +69,7 @@ pub async fn tracing_middleware(req: Request, next: Next) -> Response {
     trace!(
         http.method = %req.method(),
         http.user_agent = req.headers().typed_get::<UserAgent>().map(|ua| ua.to_string()).unwrap_or_default(),
-        http.content_type = req.headers().typed_get::<ContentType>().map(|ua| ua.to_string()).unwrap_or_default(), 
+        http.content_type = req.headers().typed_get::<ContentType>().map(|ua| ua.to_string()).unwrap_or_default(),
     "start request");
 
     let response = next.run(req).await;

tests/src/mock_relay.rs

@@ -25,7 +25,7 @@ use cb_common::{
     types::Chain,
     utils::{blst_pubkey_to_alloy, timestamp_of_slot_start_sec},
 };
-use cb_pbs::MAX_SIZE_SUBMIT_BLOCK;
+use cb_pbs::MAX_SIZE_SUBMIT_BLOCK_RESPONSE;
 use tokio::net::TcpListener;
 use tracing::debug;
 use tree_hash::TreeHash;
@@ -136,7 +136,7 @@ async fn handle_register_validator(
 async fn handle_submit_block(State(state): State<Arc<MockRelayState>>) -> Response {
     state.received_submit_block.fetch_add(1, Ordering::Relaxed);
     if state.large_body() {
-        (StatusCode::OK, Json(vec![1u8; 1 + MAX_SIZE_SUBMIT_BLOCK])).into_response()
+        (StatusCode::OK, Json(vec![1u8; 1 + MAX_SIZE_SUBMIT_BLOCK_RESPONSE])).into_response()
     } else {
         let response = SubmitBlindedBlockResponse::default();
         (StatusCode::OK, Json(response)).into_response()