Enforce consensus block size limit

Author: Ash-L2L

lib/state/block.rs

@@ -26,6 +26,12 @@ pub fn validate(
     header: &Header,
     body: &Body,
 ) -> Result<(bitcoin::Amount, MerkleRoot), Error> {
+    let body_size =
+        borsh::object_length(&body).map_err(Error::BorshSerialize)?;
+    if body_size > Body::MAX_SIZE {
+        return Err(Error::BodyTooLarge);
+    }
+
     let tip_hash = state.try_get_tip(rotxn)?;
     if header.prev_side_hash != tip_hash {
         let err = error::InvalidHeader::PrevSideHash {
@@ -123,6 +129,12 @@ pub fn prevalidate(
     header: &Header,
     body: &Body,
 ) -> Result<PrevalidatedBlock, Error> {
+    let body_size =
+        borsh::object_length(&body).map_err(Error::BorshSerialize)?;
+    if body_size > Body::MAX_SIZE {
+        return Err(Error::BodyTooLarge);
+    }
+
     let tip_hash = state.try_get_tip(rotxn)?;
     if header.prev_side_hash != tip_hash {
         let err = error::InvalidHeader::PrevSideHash {
@@ -131,6 +143,7 @@ pub fn prevalidate(
         };
         return Err(Error::InvalidHeader(err));
     };
+
     let mut coinbase_value = bitcoin::Amount::ZERO;
     for output in &body.coinbase {
         coinbase_value = coinbase_value

lib/state/error.rs

@@ -180,6 +180,8 @@ pub enum Error {
     BitName(#[from] BitName),
     #[error("bitname {name_hash} already registered")]
     BitNameAlreadyRegistered { name_hash: BitNameId },
+    #[error("body too large")]
+    BodyTooLarge,
     #[error("bundle too heavy {weight} > {max_weight}")]
     BundleTooHeavy { weight: u64, max_weight: u64 },
     #[error(transparent)]

types/lib.rs

@@ -572,6 +572,9 @@ impl Body {
         }
     }
 
+    /// Size limit in bytes
+    pub const MAX_SIZE: usize = 8 * 1024 * 1024;
+
     pub fn authorized_transactions(&self) -> Vec<AuthorizedTransaction> {
         let mut authorizations_iter = self.authorizations.iter();
         self.transactions