From c4d30751d315ff09d29c38342c6f0f042e41e80d Mon Sep 17 00:00:00 2001
From: Gianmarco Fraccaroli <gianmarco.fraccaroli@gmail.com>
Date: Wed, 29 May 2024 11:05:59 +0200
Subject: [PATCH] allow governance to change ibc storage

---
 crates/ibc/src/storage.rs                     | 22 ++++++++++++++++
 crates/namada/src/ledger/native_vp/ibc/mod.rs | 25 +++++++++++++++++++
 2 files changed, 47 insertions(+)

diff --git a/crates/ibc/src/storage.rs b/crates/ibc/src/storage.rs
index c9fa19839a..5190962be5 100644
--- a/crates/ibc/src/storage.rs
+++ b/crates/ibc/src/storage.rs
@@ -542,6 +542,28 @@ pub fn is_ibc_trace_key(key: &Key) -> Option<(String, String)> {
     }
 }
 
+/// Check if a key is an IBC parameter Key
+pub fn is_params_key(key: &Key) -> bool {
+    match &key.segments[..] {
+        [
+            DbKeySeg::AddressSeg(addr),
+            DbKeySeg::StringSeg(prefix),
+            DbKeySeg::StringSeg(_),
+        ] => {
+            if addr == &Address::Internal(InternalAddress::Ibc)
+                && (prefix == MINT_LIMIT
+                    || prefix == THROUGHPUT_LIMIT
+                    || prefix == PARAMS)
+            {
+                true
+            } else {
+                false
+            }
+        }
+        _ => false,
+    }
+}
+
 /// Returns true if the given key is for an IBC counter for clients,
 /// connections, or channelEnds
 pub fn is_ibc_counter_key(key: &Key) -> bool {
diff --git a/crates/namada/src/ledger/native_vp/ibc/mod.rs b/crates/namada/src/ledger/native_vp/ibc/mod.rs
index a0e1f41bbd..64cf7355f7 100644
--- a/crates/namada/src/ledger/native_vp/ibc/mod.rs
+++ b/crates/namada/src/ledger/native_vp/ibc/mod.rs
@@ -13,7 +13,9 @@ use namada_core::arith::{self, checked};
 use namada_core::collections::HashSet;
 use namada_core::storage::Key;
 use namada_gas::{IBC_ACTION_EXECUTE_GAS, IBC_ACTION_VALIDATE_GAS};
+use namada_governance::is_proposal_accepted;
 use namada_ibc::event::IbcEvent;
+use namada_ibc::storage::{is_params_key, params_key};
 use namada_ibc::{
     Error as ActionError, IbcActions, NftTransferModule, TransferModule,
     ValidationParams,
@@ -43,6 +45,8 @@ pub enum Error {
     NativeVpError(#[from] native_vp::Error),
     #[error("IBC VP error: Decoding error: {0}")]
     Decoding(#[from] std::io::Error),
+    #[error("IBC VP error: governance proposal change is invalid")]
+    InvalidGovernanceChange,
     #[error("IBC VP error: IBC message is required as transaction data")]
     NoTxData,
     #[error("IBC VP error: IBC action error: {0}")]
@@ -83,6 +87,27 @@ where
         keys_changed: &BTreeSet<Key>,
         _verifiers: &BTreeSet<Address>,
     ) -> VpResult<()> {
+        // Is VP triggered by a governance proposal?
+        let is_governance_proposal = is_proposal_accepted(
+            &self.ctx.pre(),
+            batched_tx
+                .tx
+                .data(batched_tx.cmt)
+                .unwrap_or_default()
+                .as_ref(),
+        )
+        .unwrap_or_default();
+
+        if is_governance_proposal {
+            let changed_keys_are_params =
+                keys_changed.iter().any(|key| is_ibc_key(key));
+            if changed_keys_are_params {
+                return Ok(());
+            } else {
+                return Err(Error::InvalidGovernanceChange);
+            }
+        }
+
         let tx_data =
             batched_tx.tx.data(batched_tx.cmt).ok_or(Error::NoTxData)?;