feat: flashloans

Cargo.toml

@@ -2,6 +2,7 @@
 members = [
     "contracts/dao/cwd-core",
     "contracts/dao/neutron-chain-manager",
+    "contracts/dao/neutron-flashloans",
     "contracts/dao/proposal/*",
     "contracts/dao/pre-propose/*",
     "contracts/dao/voting/*",

contracts/dao/neutron-chain-manager/schema/neutron-chain-manager.json

@@ -1,6 +1,6 @@
 {
   "contract_name": "neutron-chain-manager",
-  "contract_version": "0.3.0",
+  "contract_version": "0.4.0",
   "idl_version": "1.0.0",
   "instantiate": {
     "$schema": "http://json-schema.org/draft-07/schema#",
@@ -1985,6 +1985,18 @@
               }
             },
             "additionalProperties": false
+          },
+          {
+            "type": "object",
+            "required": [
+              "software_upgrade_permission"
+            ],
+            "properties": {
+              "software_upgrade_permission": {
+                "$ref": "#/definitions/SoftwareUpgradePermission"
+              }
+            },
+            "additionalProperties": false
           }
         ]
       },
@@ -2108,6 +2120,21 @@
           }
         }
       },
+      "SoftwareUpgradePermission": {
+        "type": "object",
+        "required": [
+          "cancel_upgrade",
+          "upgrade"
+        ],
+        "properties": {
+          "cancel_upgrade": {
+            "type": "boolean"
+          },
+          "upgrade": {
+            "type": "boolean"
+          }
+        }
+      },
       "SoftwareUpgradeProposal": {
         "description": "Deprecated. SoftwareUpgradeProposal defines the struct for software upgrade proposal.",
         "deprecated": true,
@@ -2698,9 +2725,36 @@
                 }
               },
               "additionalProperties": false
+            },
+            {
+              "type": "object",
+              "required": [
+                "software_upgrade_permission"
+              ],
+              "properties": {
+                "software_upgrade_permission": {
+                  "$ref": "#/definitions/SoftwareUpgradePermission"
+                }
+              },
+              "additionalProperties": false
             }
           ]
         },
+        "SoftwareUpgradePermission": {
+          "type": "object",
+          "required": [
+            "cancel_upgrade",
+            "upgrade"
+          ],
+          "properties": {
+            "cancel_upgrade": {
+              "type": "boolean"
+            },
+            "upgrade": {
+              "type": "boolean"
+            }
+          }
+        },
         "StrategyMsg": {
           "oneOf": [
             {

contracts/dao/neutron-chain-manager/schema/raw/execute.json

@@ -1956,6 +1956,18 @@
             }
           },
           "additionalProperties": false
+        },
+        {
+          "type": "object",
+          "required": [
+            "software_upgrade_permission"
+          ],
+          "properties": {
+            "software_upgrade_permission": {
+              "$ref": "#/definitions/SoftwareUpgradePermission"
+            }
+          },
+          "additionalProperties": false
         }
       ]
     },
@@ -2079,6 +2091,21 @@
         }
       }
     },
+    "SoftwareUpgradePermission": {
+      "type": "object",
+      "required": [
+        "cancel_upgrade",
+        "upgrade"
+      ],
+      "properties": {
+        "cancel_upgrade": {
+          "type": "boolean"
+        },
+        "upgrade": {
+          "type": "boolean"
+        }
+      }
+    },
     "SoftwareUpgradeProposal": {
       "description": "Deprecated. SoftwareUpgradeProposal defines the struct for software upgrade proposal.",
       "deprecated": true,

contracts/dao/neutron-chain-manager/schema/raw/response_to_strategies.json

@@ -154,9 +154,36 @@
             }
           },
           "additionalProperties": false
+        },
+        {
+          "type": "object",
+          "required": [
+            "software_upgrade_permission"
+          ],
+          "properties": {
+            "software_upgrade_permission": {
+              "$ref": "#/definitions/SoftwareUpgradePermission"
+            }
+          },
+          "additionalProperties": false
         }
       ]
     },
+    "SoftwareUpgradePermission": {
+      "type": "object",
+      "required": [
+        "cancel_upgrade",
+        "upgrade"
+      ],
+      "properties": {
+        "cancel_upgrade": {
+          "type": "boolean"
+        },
+        "upgrade": {
+          "type": "boolean"
+        }
+      }
+    },
     "StrategyMsg": {
       "oneOf": [
         {

contracts/dao/neutron-flashloans/.cargo/config

@@ -0,0 +1,4 @@
+[alias]
+wasm = "build --release --target wasm32-unknown-unknown"
+unit-test = "test --lib"
+schema = "run --example neutron-flashloans_schema"

contracts/dao/neutron-flashloans/.gitignore

@@ -0,0 +1,15 @@
+# Build results
+/target
+
+# Cargo+Git helper file (https://github.com/rust-lang/cargo/blob/0.44.1/src/cargo/sources/git/utils.rs#L320-L327)
+.cargo-ok
+
+# Text file backups
+**/*.rs.bk
+
+# macOS
+.DS_Store
+
+# IDEs
+*.iml
+.idea

contracts/dao/neutron-flashloans/Cargo.toml

@@ -0,0 +1,41 @@
+[package]
+authors = ["Andrei Zavgorodnii <andrei.z@hadronlans.org>"]
+description = "An implementation of Flashloans for Neutron"
+edition = "2021"
+name = "neutron-flashloans"
+repository = "https://github.com/neutron-org/neutron-dao"
+version = "0.3.0"
+
+[lib]
+crate-type = ["cdylib", "rlib"]
+
+[features]
+# for more explicit tests, cargo test --features=backtraces
+backtraces = ["cosmwasm-std/backtraces"]
+# use library feature to disable all instantiate/execute/query exports
+library = []
+
+[dependencies]
+cosmwasm-schema = {version = "1.3.0"}
+cosmwasm-std = {version = "1.3.0"}
+cosmwasm-storage = {version = "1.3.0"}
+cw-controllers = "1.1.0"
+cw-paginate = {path = "../../../packages/cw-paginate"}
+cw-storage-plus = "1.1.0"
+cw-utils = {version = "1.0.1"}
+cw2 = "1.1.0"
+cwd-interface = {path = "../../../packages/cwd-interface"}
+cwd-macros = {path = "../../../packages/cwd-macros"}
+schemars = "0.8.8"
+serde = {version = "1.0.175", default-features = false, features = ["derive"]}
+serde_with = {version = "3.7.0", features = ["json"]}
+thiserror = {version = "1.0"}
+neutron-sdk = "0.8.0"
+serde-json-wasm = "1.0.1"
+prost = { version = "0.12.3", default-features = false }
+prost-types = { version = "0.12.3", default-features = false }
+cosmos-sdk-proto = { version = "0.20.0", default-features = false }
+
+[dev-dependencies]
+anyhow = "1.0.57"
+cw-multi-test = "0.16.5"

contracts/dao/neutron-flashloans/README.md

@@ -0,0 +1,66 @@
+# Neutron Flashloans
+
+## Overview
+
+The `neutron-flashloans` contract facilitates providing flash loans to smart contracts operating on the Neutron network.
+
+A flash loan is a type of uncollateralized loan in the cryptocurrency and decentralized finance (DeFi) space. It allows
+borrowers to borrow funds without providing any collateral, on the condition that the loan is repaid within the same
+transaction. If the borrower fails to repay the loan by the end of the transaction, the entire transaction is
+reversed, effectively canceling the loan. Flash loans are typically used for arbitrage, collateral swapping, and
+refinancing, taking advantage of price discrepancies or temporary liquidity needs without requiring long-term capital.
+
+## Usage
+
+To get a flash loan, a `RequestLoan` message needs to be sent to the `neutron-flashloans` contract:
+
+```rust
+struct RequestLoan {
+    /// The amount that the borrower contract requests; there should be no
+    /// duplicate denoms and no zero amounts. 
+    amount: Vec<Coin>,
+}
+```
+
+The sender needs to be a smart-contract that implements a handler for the `ProcessLoan` message:
+
+```rust
+#[cw_serde]
+pub enum BorrowerInterface {
+    ProcessLoan {
+        /// Specifies the address to which the borrower must return the loan amount AND pay the fees.
+        return_address: Addr,
+        /// Specifies the loan amount which the borrower must return to the return_address.
+        loan_amount: Vec<Coin>,
+        /// Specifies the fee which the borrower must pay to the return_address.
+        fee: Vec<Coin>,
+    }
+}
+```
+
+Upon receiving the `RequestLoan` message, the `neutron-flashloans` contract will transfer the requested amount to the
+borrower and send a `ProcessLoan` message. The borrower can execute any logic within its `ProcessLoan` handler but must
+return the `loan_amount` plus the `fee` to the `return_address`. Failure to do so will result in the entire transaction
+being reverted.
+
+## Implementation
+
+The `neutron-flashloans` contract does not hold any funds. Instead, it uses `authz` permission from the `source` address
+to execute `/cosmos.bank.v1beta1.MsgSend` on its behalf. For Neutron, the `source` address must be set to the Treasury (
+DAO core) contract address.
+
+* The `RequestLoan` handler ensures there is no active loan, validates the loan amount (no duplicate or zero coins),
+  calculates the expected balance (current balance + fee) of the source after repayment, and records the loan details in
+  storage. If the `source` does not have the requested amount of funds, an error will be returned. Finally, it instructs
+  the source to send the requested amount to the borrower via `authz`, encapsulated in a `stargate message`. This
+  message is submitted as a submessage with a `reply_on_success` strategy, meaning if it fails, the transaction is
+  reverted.
+* Upon successful execution of the `/cosmos.bank.v1beta1.MsgSend` message, the `neutron-flashloans` contract sends
+  a `ProcessLoan` submessage with a `reply_on_success` strategy to the borrower contract.
+* After receiving a successful reply to the `ProcessLoan` message, the `neutron-flashloans` contract verifies that the
+  borrower has returned the funds and paid the fee, then it deletes the loan information.
+
+## Security advice
+
+When writing a borrower contract, ensure that the `ProcessLoan` handler has proper permissions. It should only be
+callable when your contract has previously requested a loan and only by the `neutron-flashloans` contract.

contracts/dao/neutron-flashloans/examples/neutron-flashloans_schema.rs

@@ -0,0 +1,11 @@
+use cosmwasm_schema::write_api;
+use neutron_flashloans::msg::{ExecuteMsg, InstantiateMsg, MigrateMsg, QueryMsg};
+
+fn main() {
+    write_api! {
+        instantiate: InstantiateMsg,
+        query: QueryMsg,
+        execute: ExecuteMsg,
+        migrate: MigrateMsg
+    }
+}