fix: Shareholders Can Clear Frozen Position Rewards

.prettierrc

@@ -0,0 +1 @@
+{}

CHANGELOG.md

@@ -26,6 +26,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 ### Changed
 
 - Update anchor to `1.0.2`
+- The `fund_by_claiming_fee` endpoint now rejects when `skip_reward` is non-zero for DAMM v2 `claim_reward` instruction to prevent clearing pending rewards without funding the `FeeVault`
 
 ## dynamic-fee-sharing [0.1.1] [PR #8](https://github.com/MeteoraAg/dynamic-fee-sharing/pull/8)
 

programs/dynamic-fee-sharing/src/error.rs

@@ -34,4 +34,7 @@ pub enum FeeVaultError {
 
     #[msg("Invalid action")]
     InvalidAction,
+
+    #[msg("Invalid parameters")]
+    InvalidParameters,
 }

programs/dynamic-fee-sharing/src/instructions/ix_fund_by_claiming_fee.rs

@@ -22,7 +22,7 @@ pub struct FundByClaimingFeeCtx<'info> {
     pub source_program: UncheckedAccount<'info>,
 }
 
-pub fn is_support_action<'info>(
+fn is_support_action<'info>(
     source_program: &Pubkey,
     discriminator: &[u8],
     token_vault: Pubkey,
@@ -38,11 +38,29 @@ pub fn is_support_action<'info>(
     false
 }
 
+fn validate_payload(source_program: &Pubkey, discriminator: &[u8], payload: &[u8]) -> Result<()> {
+    if source_program.eq(&damm_v2::ID)
+        && discriminator == damm_v2::client::args::ClaimReward::DISCRIMINATOR
+    {
+        let args = damm_v2::client::args::ClaimReward::try_from_slice(&payload[8..])
+            .map_err(|_| FeeVaultError::InvalidAction)?;
+
+        // when skip_reward == 1 and the token_account is frozen, damm_v2 clears the pending reward without transferring it
+        // so skipping the reward is not allowed when funding the FeeVault
+        require!(args.skip_reward == 0, FeeVaultError::InvalidParameters);
+    }
+
+    Ok(())
+}
+
 pub fn handle_fund_by_claiming_fee(
     ctx: Context<FundByClaimingFeeCtx>,
     payload: Vec<u8>,
 ) -> Result<()> {
+    require!(payload.len() >= 8, FeeVaultError::InvalidAction);
+
     let discriminator = &payload[..8]; // first 8 bytes is discriminator
+
     require!(
         is_support_action(
             ctx.accounts.source_program.key,
@@ -53,6 +71,8 @@ pub fn handle_fund_by_claiming_fee(
         FeeVaultError::InvalidAction
     );
 
+    validate_payload(ctx.accounts.source_program.key, &discriminator, &payload)?;
+
     let fee_vault = ctx.accounts.fee_vault.load()?;
 
     require!(

tests/claim_damm_v2.test.ts

@@ -7,7 +7,12 @@ import {
   startSvm,
   warpToTimestamp,
 } from "./common/svm";
-import { createToken, getFeeVault, mintToken } from "./common";
+import {
+  createToken,
+  getFeeVault,
+  getProgramErrorCodeHexString,
+  mintToken,
+} from "./common";
 import {
   createDammV2Pool,
   dammV2Swap,
@@ -213,4 +218,66 @@ describe("Fund by claiming damm v2", () => {
     );
     expect(Number(postFeePerShare.sub(preFeePerShare))).gt(0);
   });
+
+  it("Reject claiming damm v2 reward with skip_reward set", async () => {
+    const { feeVault, tokenVault } = await createFeeVaultPda(
+      svm,
+      admin,
+      vaultOwner.publicKey,
+      rewardMint,
+      {
+        padding: [],
+        users: [
+          {
+            address: shareHolder.publicKey,
+            share: 100,
+          },
+          {
+            address: PublicKey.unique(),
+            share: 100,
+          },
+        ],
+      }
+    );
+
+    const setAuthorityIx = createSetAuthorityInstruction(
+      positionNftAccount,
+      creator.publicKey,
+      AuthorityType.AccountOwner,
+      feeVault,
+      [],
+      TOKEN_2022_PROGRAM_ID
+    );
+    const assignOwnerTx = new Transaction().add(setAuthorityIx);
+    assignOwnerTx.recentBlockhash = svm.latestBlockhash();
+    assignOwnerTx.sign(creator);
+
+    sendTransactionOrExpectThrowError(svm, assignOwnerTx);
+
+    const rewardIndex = 0;
+    await initializeAndFundReward(
+      svm,
+      creator,
+      dammV2Pool,
+      rewardMint,
+      rewardIndex
+    );
+
+    warpToTimestamp(svm, new BN(12 * 60 * 60));
+
+    const errorCode = getProgramErrorCodeHexString("InvalidParameters");
+    await claimDammV2Reward(
+      svm,
+      shareHolder,
+      creator,
+      feeVault,
+      tokenVault,
+      dammV2Pool,
+      position,
+      positionNftAccount,
+      rewardIndex,
+      true,
+      errorCode
+    );
+  });
 });

tests/common/dfs.ts

@@ -76,7 +76,8 @@ async function fundByClaimingFee(
   tokenVault: PublicKey,
   remainingAccounts: AccountMeta[],
   payload: Buffer,
-  sourceProgram: PublicKey
+  sourceProgram: PublicKey,
+  errorCode?: number
 ) {
   const program = createProgram();
 
@@ -94,7 +95,7 @@ async function fundByClaimingFee(
   tx.recentBlockhash = svm.latestBlockhash();
   tx.sign(signer);
 
-  const result = sendTransactionOrExpectThrowError(svm, tx);
+  const result = sendTransactionOrExpectThrowError(svm, tx, false, errorCode);
 
   return result;
 }
@@ -222,7 +223,9 @@ export async function claimDammV2Reward(
   dammv2Pool: PublicKey,
   position: PublicKey,
   positionNftAccount: PublicKey,
-  rewardIndex: number
+  rewardIndex: number,
+  skipReward = false,
+  errorCode?: number
 ) {
   const dammV2PoolState = getDammV2PoolState(svm, dammv2Pool);
 
@@ -292,7 +295,7 @@ export async function claimDammV2Reward(
   const payload = Buffer.concat([
     Buffer.from(claimDammV2RewardDisc),
     Buffer.from([rewardIndex]),
-    Buffer.from([1]),
+    Buffer.from([Number(skipReward)]),
   ]);
   await fundByClaimingFee(
     svm,
@@ -301,7 +304,8 @@ export async function claimDammV2Reward(
     tokenVault,
     remainingAccounts,
     payload,
-    DAMM_V2_PROGRAM_ID
+    DAMM_V2_PROGRAM_ID,
+    errorCode
   );
 }