Flashloans

programs/marginfi/src/errors.rs

@@ -79,9 +79,15 @@ pub enum MarginfiError {
     EmissionsUpdateError,
     #[msg("Account disabled")] // 6037
     AccountDisabled,
-    #[msg("Account can't temporarily open new balances, please close a balance first")]
+    #[msg("Account can't temporarily open 3 balances, please close a balance first")] // 6038
     AccountTempActiveBalanceLimitExceeded,
-    #[msg("Illegal balance state")] // 6038
+    #[msg("Illegal action during flashloan")] // 6039
+    AccountInFlashloan,
+    #[msg("Illegal flashloan")] // 6040
+    IllegalFlashloan,
+    #[msg("Illegal flag")] // 6041
+    IllegalFlag,
+    #[msg("Illegal balance state")] // 6043
     IllegalBalanceState,
 }
 

programs/marginfi/src/instructions/marginfi_account/borrow.rs

@@ -4,9 +4,7 @@ use crate::{
     events::{AccountEventHeader, LendingAccountBorrowEvent},
     prelude::{MarginfiError, MarginfiGroup, MarginfiResult},
     state::{
-        marginfi_account::{
-            BankAccountWrapper, MarginfiAccount, RiskEngine, RiskRequirementType, DISABLED_FLAG,
-        },
+        marginfi_account::{BankAccountWrapper, MarginfiAccount, RiskEngine, DISABLED_FLAG},
         marginfi_group::{Bank, BankVaultType},
     },
 };
@@ -87,8 +85,7 @@ pub fn lending_account_borrow(ctx: Context<LendingAccountBorrow>, amount: u64) -
 
     // Check account health, if below threshold fail transaction
     // Assuming `ctx.remaining_accounts` holds only oracle accounts
-    RiskEngine::new(&marginfi_account, ctx.remaining_accounts)?
-        .check_account_health(RiskRequirementType::Initial)?;
+    RiskEngine::check_account_init_health(&marginfi_account, ctx.remaining_accounts)?;
 
     Ok(())
 }

programs/marginfi/src/instructions/marginfi_account/flashloan.rs

@@ -0,0 +1,147 @@
+use anchor_lang::{prelude::*, Discriminator};
+use solana_program::{
+    instruction::{get_stack_height, TRANSACTION_LEVEL_STACK_HEIGHT},
+    sysvar::{self, instructions},
+};
+
+use crate::{
+    check,
+    prelude::*,
+    state::marginfi_account::{
+        MarginfiAccount, RiskEngine, DISABLED_FLAG, FLASHLOAN_ENABLED_FLAG, IN_FLASHLOAN_FLAG,
+    },
+};
+
+pub fn lending_account_start_flashloan(
+    ctx: Context<LendingAccountStartFlashloan>,
+    end_index: u64,
+) -> MarginfiResult<()> {
+    check_flashloan_can_start(
+        &ctx.accounts.marginfi_account,
+        &ctx.accounts.ixs_sysvar,
+        end_index as usize,
+    )?;
+
+    let mut marginfi_account = ctx.accounts.marginfi_account.load_mut()?;
+    marginfi_account.set_flag(IN_FLASHLOAN_FLAG);
+
+    Ok(())
+}
+
+#[derive(Accounts)]
+pub struct LendingAccountStartFlashloan<'info> {
+    #[account(mut)]
+    pub marginfi_account: AccountLoader<'info, MarginfiAccount>,
+    #[account(address = marginfi_account.load()?.authority)]
+    pub signer: Signer<'info>,
+    /// CHECK: Instructions sysvar
+    #[account(address = sysvar::instructions::ID)]
+    pub ixs_sysvar: AccountInfo<'info>,
+}
+
+const END_FL_IX_MARGINFI_ACCOUNT_AI_IDX: usize = 0;
+
+/// Checklist
+/// 1. `end_flashloan` ix index is after `start_flashloan` ix index
+/// 2. Ixs has an `end_flashloan` ix present
+/// 3. `end_flashloan` ix is for the marginfi program
+/// 3. `end_flashloan` ix is for the same marginfi account
+/// 4. Account is not disabled
+/// 5. Account is not already in a flashloan
+/// 6. Start flashloan ix is not in CPI
+/// 7. End flashloan ix is not in CPI
+pub fn check_flashloan_can_start(
+    marginfi_account: &AccountLoader<MarginfiAccount>,
+    sysvar_ixs: &AccountInfo,
+    end_fl_idx: usize,
+) -> MarginfiResult<()> {
+    check!(
+        marginfi_account.load()?.get_flag(FLASHLOAN_ENABLED_FLAG),
+        MarginfiError::IllegalFlashloan
+    );
+
+    let current_ix_idx: usize = instructions::load_current_index_checked(sysvar_ixs)?.into();
+
+    check!(current_ix_idx < end_fl_idx, MarginfiError::IllegalFlashloan);
+
+    // Check current ix is not a CPI
+    let current_ix = instructions::load_instruction_at_checked(current_ix_idx, sysvar_ixs)?;
+
+    check!(
+        get_stack_height() == TRANSACTION_LEVEL_STACK_HEIGHT,
+        MarginfiError::IllegalFlashloan,
+        "Start flashloan ix should not be in CPI"
+    );
+
+    check!(
+        current_ix.program_id.eq(&crate::id()),
+        MarginfiError::IllegalFlashloan,
+        "Start flashloan ix should not be in CPI"
+    );
+
+    // Will error if ix doesn't exist
+    let unchecked_end_fl_ix = instructions::load_instruction_at_checked(end_fl_idx, sysvar_ixs)?;
+
+    check!(
+        unchecked_end_fl_ix.data[..8]
+            .eq(&crate::instruction::LendingAccountEndFlashloan::DISCRIMINATOR),
+        MarginfiError::IllegalFlashloan
+    );
+
+    check!(
+        unchecked_end_fl_ix.program_id.eq(&crate::id()),
+        MarginfiError::IllegalFlashloan
+    );
+
+    let end_fl_ix = unchecked_end_fl_ix;
+
+    let end_fl_marginfi_account = end_fl_ix
+        .accounts
+        .get(END_FL_IX_MARGINFI_ACCOUNT_AI_IDX)
+        .ok_or(MarginfiError::IllegalFlashloan)?;
+
+    check!(
+        end_fl_marginfi_account.pubkey.eq(&marginfi_account.key()),
+        MarginfiError::IllegalFlashloan
+    );
+
+    let marginf_account = marginfi_account.load()?;
+
+    check!(
+        !marginf_account.get_flag(DISABLED_FLAG),
+        MarginfiError::AccountDisabled
+    );
+
+    check!(
+        !marginf_account.get_flag(IN_FLASHLOAN_FLAG),
+        MarginfiError::IllegalFlashloan
+    );
+
+    Ok(())
+}
+
+pub fn lending_account_end_flashloan(
+    ctx: Context<LendingAccountEndFlashloan>,
+) -> MarginfiResult<()> {
+    check!(
+        get_stack_height() == TRANSACTION_LEVEL_STACK_HEIGHT,
+        MarginfiError::IllegalFlashloan,
+        "End flashloan ix should not be in CPI"
+    );
+
+    let mut marginfi_account = ctx.accounts.marginfi_account.load_mut()?;
+
+    marginfi_account.unset_flag(IN_FLASHLOAN_FLAG);
+
+    RiskEngine::check_account_init_health(&marginfi_account, ctx.remaining_accounts)?;
+
+    Ok(())
+}
+
+#[derive(Accounts)]
+pub struct LendingAccountEndFlashloan<'info> {
+    #[account(mut)]
+    pub marginfi_account: AccountLoader<'info, MarginfiAccount>,
+    #[account(address = marginfi_account.load()?.authority)]
+    pub signer: Signer<'info>,
+}

programs/marginfi/src/instructions/marginfi_account/liquidate.rs

@@ -2,7 +2,7 @@ use crate::constants::{
     INSURANCE_VAULT_SEED, LIQUIDATION_INSURANCE_FEE, LIQUIDATION_LIQUIDATOR_FEE, MAX_PRICE_AGE_SEC,
 };
 use crate::events::{AccountEventHeader, LendingAccountLiquidateEvent, LiquidationBalances};
-use crate::state::marginfi_account::{calc_amount, calc_value, RiskEngine, RiskRequirementType};
+use crate::state::marginfi_account::{calc_amount, calc_value, RiskEngine};
 use crate::state::marginfi_group::{Bank, BankVaultType};
 use crate::state::price::{OraclePriceFeedAdapter, OraclePriceType, PriceAdapter, PriceBias};
 use crate::{
@@ -343,8 +343,10 @@ pub fn lending_account_liquidate(
             )?;
 
     // Verify liquidator account health
-    RiskEngine::new(&liquidator_marginfi_account, liquidator_remaining_accounts)?
-        .check_account_health(RiskRequirementType::Initial)?;
+    RiskEngine::check_account_init_health(
+        &liquidator_marginfi_account,
+        liquidator_remaining_accounts,
+    )?;
 
     emit!(LendingAccountLiquidateEvent {
         header: AccountEventHeader {

programs/marginfi/src/instructions/marginfi_account/mod.rs

@@ -2,6 +2,7 @@ mod borrow;
 mod close_balance;
 mod deposit;
 mod emissions;
+mod flashloan;
 mod initialize;
 mod liquidate;
 mod repay;
@@ -11,6 +12,7 @@ pub use borrow::*;
 pub use close_balance::*;
 pub use deposit::*;
 pub use emissions::*;
+pub use flashloan::*;
 pub use initialize::*;
 pub use liquidate::*;
 pub use repay::*;

programs/marginfi/src/instructions/marginfi_account/withdraw.rs

@@ -4,9 +4,7 @@ use crate::{
     events::{AccountEventHeader, LendingAccountWithdrawEvent},
     prelude::*,
     state::{
-        marginfi_account::{
-            BankAccountWrapper, MarginfiAccount, RiskEngine, RiskRequirementType, DISABLED_FLAG,
-        },
+        marginfi_account::{BankAccountWrapper, MarginfiAccount, RiskEngine, DISABLED_FLAG},
         marginfi_group::{Bank, BankVaultType},
     },
 };
@@ -100,8 +98,7 @@ pub fn lending_account_withdraw(
 
     // Check account health, if below threshold fail transaction
     // Assuming `ctx.remaining_accounts` holds only oracle accounts
-    RiskEngine::new(&marginfi_account, ctx.remaining_accounts)?
-        .check_account_health(RiskRequirementType::Initial)?;
+    RiskEngine::check_account_init_health(&marginfi_account, ctx.remaining_accounts)?;
 
     Ok(())
 }

programs/marginfi/src/instructions/marginfi_group/configure.rs

@@ -1,4 +1,7 @@
+use crate::check;
 use crate::events::{GroupEventHeader, MarginfiGroupConfigureEvent};
+use crate::prelude::MarginfiError;
+use crate::state::marginfi_account::{MarginfiAccount, FLASHLOAN_ENABLED_FLAG};
 use crate::{
     state::marginfi_group::{GroupConfig, MarginfiGroup},
     MarginfiResult,
@@ -34,3 +37,91 @@ pub struct MarginfiGroupConfigure<'info> {
     )]
     pub admin: Signer<'info>,
 }
+
+/// Only these flags can be configured
+///
+/// Example:
+/// CONFIGURABLE_FLAGS = 0b0110
+///
+/// 0b0010 is a valid flag
+/// 0b0110 is a valid flag
+/// 0b1000 is not a valid flag
+/// 0b0101 is not a valid flag
+const CONFIGURABLE_FLAGS: u64 = FLASHLOAN_ENABLED_FLAG;
+
+fn flag_can_be_set(flag: u64) -> bool {
+    // If bitwise AND operation between flag and its bitwise NOT of CONFIGURABLE_FLAGS is 0,
+    // it means no bit in flag is set outside the configurable bits.
+    (flag & !CONFIGURABLE_FLAGS) == 0
+}
+
+pub fn set_account_flag(ctx: Context<SetAccountFlag>, flag: u64) -> MarginfiResult {
+    check!(flag_can_be_set(flag), MarginfiError::IllegalFlag);
+
+    let mut marginfi_account = ctx.accounts.marginfi_account.load_mut()?;
+
+    marginfi_account.set_flag(flag);
+
+    Ok(())
+}
+
+#[derive(Accounts)]
+pub struct SetAccountFlag<'info> {
+    #[account(address = marginfi_account.load()?.group)]
+    pub marginfi_group: AccountLoader<'info, MarginfiGroup>,
+
+    #[account(mut)]
+    pub marginfi_account: AccountLoader<'info, MarginfiAccount>,
+
+    /// Admin only
+    #[account(address = marginfi_group.load()?.admin)]
+    pub admin: Signer<'info>,
+}
+
+pub fn unset_account_flag(ctx: Context<UnsetAccountFlag>, flag: u64) -> MarginfiResult {
+    check!(flag_can_be_set(flag), MarginfiError::IllegalFlag);
+
+    let mut marginfi_account = ctx.accounts.marginfi_account.load_mut()?;
+
+    marginfi_account.unset_flag(flag);
+
+    Ok(())
+}
+
+#[derive(Accounts)]
+pub struct UnsetAccountFlag<'info> {
+    #[account(address = marginfi_account.load()?.group)]
+    pub marginfi_group: AccountLoader<'info, MarginfiGroup>,
+
+    #[account(mut)]
+    pub marginfi_account: AccountLoader<'info, MarginfiAccount>,
+
+    /// Admin only
+    #[account(address = marginfi_group.load()?.admin)]
+    pub admin: Signer<'info>,
+}
+
+#[cfg(test)]
+mod tests {
+    use crate::state::marginfi_account::{
+        DISABLED_FLAG, FLASHLOAN_ENABLED_FLAG, IN_FLASHLOAN_FLAG,
+    };
+
+    #[test]
+    ///
+    /// 0b0001 is a valid flag
+    /// 0b0011 is a invalid flag
+    /// 0b0101 is a invalid flag
+    /// 0b1000 is a invalid flag
+    fn test_check_flag() {
+        let flag1 = FLASHLOAN_ENABLED_FLAG;
+        let flag2 = FLASHLOAN_ENABLED_FLAG + IN_FLASHLOAN_FLAG;
+        let flag3 = IN_FLASHLOAN_FLAG + DISABLED_FLAG + FLASHLOAN_ENABLED_FLAG;
+        let flag4 = DISABLED_FLAG + IN_FLASHLOAN_FLAG;
+
+        assert!(super::flag_can_be_set(flag1));
+        assert!(!super::flag_can_be_set(flag2));
+        assert!(!super::flag_can_be_set(flag3));
+        assert!(!super::flag_can_be_set(flag4));
+    }
+}

programs/marginfi/src/lib.rs

@@ -144,6 +144,19 @@ pub mod marginfi {
         marginfi_account::lending_account_liquidate(ctx, asset_amount)
     }
 
+    pub fn lending_account_start_flashloan(
+        ctx: Context<LendingAccountStartFlashloan>,
+        end_index: u64,
+    ) -> MarginfiResult {
+        marginfi_account::lending_account_start_flashloan(ctx, end_index)
+    }
+
+    pub fn lending_account_end_flashloan(
+        ctx: Context<LendingAccountEndFlashloan>,
+    ) -> MarginfiResult {
+        marginfi_account::lending_account_end_flashloan(ctx)
+    }
+
     // Operational instructions
     pub fn lending_pool_accrue_bank_interest(
         ctx: Context<LendingPoolAccrueBankInterest>,
@@ -156,4 +169,12 @@ pub mod marginfi {
     ) -> MarginfiResult {
         marginfi_group::lending_pool_collect_bank_fees(ctx)
     }
+
+    pub fn set_account_flag(ctx: Context<SetAccountFlag>, flag: u64) -> MarginfiResult {
+        marginfi_group::set_account_flag(ctx, flag)
+    }
+
+    pub fn unset_account_flag(ctx: Context<UnsetAccountFlag>, flag: u64) -> MarginfiResult {
+        marginfi_group::unset_account_flag(ctx, flag)
+    }
 }