helper function for custodian check

Author: Bengt Lofgren

solana/programs/matching-engine/src/fallback/processor/execute_order.rs

@@ -1,5 +1,5 @@
-use super::helpers::require_min_account_infos_len;
 use crate::fallback::burn_and_post::PostMessageDerivedAccounts;
+use crate::fallback::helpers::*;
 use crate::state::{
     Auction, AuctionConfig, AuctionStatus, Custodian, FastMarketOrder as FastMarketOrderState,
     MessageProtocol, RouterEndpoint,
@@ -222,15 +222,7 @@ pub fn handle_execute_order_shim(accounts: &[AccountInfo]) -> Result<()> {
     };
 
     // Check custodian owner
-    if custodian_account.owner != &ID {
-        msg!(
-            "Custodian owner is invalid: expected {}, got {}",
-            &ID,
-            custodian_account.owner
-        );
-        return Err(ErrorCode::ConstraintOwner.into())
-            .map_err(|e: Error| e.with_account_name("custodian"));
-    };
+    check_custodian_owner_is_program_id(custodian_account)?;
 
     // Check custodian deserialises into a checked custodian account
     let _checked_custodian = Custodian::try_deserialize(&mut &custodian_account.data.borrow()[..])?;

solana/programs/matching-engine/src/fallback/processor/helpers.rs

@@ -1,5 +1,6 @@
 use anchor_lang::prelude::*;
 
+use crate::ID;
 use anchor_spl::mint::USDC;
 use anchor_spl::token::spl_token;
 use solana_program::program_pack::Pack;
@@ -18,6 +19,12 @@ pub fn require_min_account_infos_len(accounts: &[AccountInfo], len: usize) -> Re
     Ok(())
 }
 
+#[inline(always)]
+pub fn check_custodian_owner_is_program_id(custodian: &AccountInfo) -> Result<()> {
+    require_eq!(custodian.owner, &ID, ErrorCode::ConstraintOwner);
+    Ok(())
+}
+
 pub fn create_account_reliably(
     payer_key: &Pubkey,
     account_key: &Pubkey,

solana/programs/matching-engine/src/fallback/processor/place_initial_offer.rs

@@ -1,6 +1,4 @@
-use super::helpers::create_account_reliably;
-use super::helpers::create_usdc_token_account_reliably;
-use super::helpers::require_min_account_infos_len;
+use super::helpers::*;
 use crate::state::MessageProtocol;
 use crate::state::{
     Auction, AuctionConfig, AuctionInfo, AuctionStatus, Custodian,
@@ -239,15 +237,8 @@ pub fn place_initial_offer_cctp_shim(
     }
 
     // Check custodian owner
-    if custodian.owner != program_id {
-        msg!(
-            "Custodian owner is invalid: expected {}, got {}",
-            program_id,
-            custodian.owner
-        );
-        return Err(ErrorCode::ConstraintOwner.into())
-            .map_err(|e: Error| e.with_account_name("custodian"));
-    }
+    check_custodian_owner_is_program_id(custodian)?;
+
     // Check custodian is not paused
     let checked_custodian = Custodian::try_deserialize(&mut &custodian.data.borrow()[..])?;
     if checked_custodian.paused {

solana/programs/matching-engine/src/fallback/processor/prepare_order_response.rs

@@ -3,6 +3,7 @@ use std::io::Cursor;
 use super::helpers::create_account_reliably;
 use super::place_initial_offer::VaaMessageBodyHeader;
 use super::FallbackMatchingEngineInstruction;
+use crate::fallback::helpers::check_custodian_owner_is_program_id;
 use crate::fallback::helpers::create_usdc_token_account_reliably;
 use crate::fallback::helpers::require_min_account_infos_len;
 use crate::state::PreparedOrderResponseInfo;
@@ -227,6 +228,8 @@ pub fn prepare_order_response_cctp_shim(
         ErrorCode::ConstraintOwner
     );
 
+    // Check custodian owner
+    check_custodian_owner_is_program_id(custodian)?;
     // Check that custodian deserializes correctly
     let _checked_custodian =
         Custodian::try_deserialize(&mut &custodian.data.borrow()[..]).map(Box::new)?;
@@ -256,9 +259,6 @@ pub fn prepare_order_response_cctp_shim(
     let (prepared_custody_token_pda, prepared_custody_token_bump) =
         Pubkey::find_program_address(&prepared_custody_token_seeds, program_id);
 
-    // Check custodian account
-    require_eq!(custodian.owner, program_id, ErrorCode::ConstraintOwner);
-
     // Check usdc mint
     require_eq!(
         usdc.key(),