feat: Add is offer flag to collaborative close offered channel

This is needed in case of a disconnect to know who offered the collaborative close. or in other words who needs to accept the collab close offer.

dlc-manager/src/channel/ser.rs

@@ -62,7 +62,7 @@ impl_dlc_writeable_enum!(
     (8, RenewConfirmed, {(contract_id, writeable), (offer_per_update_point, writeable), (accept_per_update_point, writeable), (buffer_transaction, writeable), (buffer_script_pubkey, writeable), (offer_buffer_adaptor_signature, {cb_writeable, write_ecdsa_adaptor_signature, read_ecdsa_adaptor_signature}), (timeout, writeable), (own_payout, writeable), (total_collateral, writeable)}),
     (10, RenewFinalized, {(contract_id, writeable), (prev_offer_per_update_point, writeable), (buffer_transaction, writeable), (buffer_script_pubkey, writeable), (offer_buffer_adaptor_signature, {cb_writeable, write_ecdsa_adaptor_signature, read_ecdsa_adaptor_signature}), (accept_buffer_adaptor_signature, {cb_writeable, write_ecdsa_adaptor_signature, read_ecdsa_adaptor_signature}), (timeout, writeable), (own_payout, writeable), (total_collateral, writeable)}),
     (9, Closing, {(buffer_transaction, writeable), (contract_id, writeable), (is_initiator, writeable)}),
-    (11, CollaborativeCloseOffered, { (counter_payout, writeable), (offer_signature, writeable), (close_tx, writeable), (timeout, writeable) })
+    (11, CollaborativeCloseOffered, { (counter_payout, writeable), (offer_signature, writeable), (close_tx, writeable), (timeout, writeable), (is_offer, writeable) })
     ;;
 );
 

dlc-manager/src/channel/signed_channel.rs

@@ -309,6 +309,8 @@ typed_enum!(
             /// The UNIX epoch at which the counter party will be considered
             /// unresponsive and the channel will be forced closed.
             timeout: u64,
+            /// Indicates whether the local party offered the collaborative close or not.
+            is_offer: bool,
         },
     },
     /// Enum automatically generated associating a number to each signed channel

dlc-manager/src/channel_updater.rs

@@ -2227,6 +2227,7 @@ where
         offer_signature: close_signature,
         close_tx: close_tx.clone(),
         timeout: time.unix_time_now() + super::manager::PEER_TIMEOUT,
+        is_offer: true,
     };
     std::mem::swap(&mut state, &mut signed_channel.state);
     signed_channel.roll_back_state = Some(state);
@@ -2285,6 +2286,7 @@ where
         offer_signature: close_offer.close_signature,
         close_tx,
         timeout: time.unix_time_now() + peer_timeout,
+        is_offer: false
     };
 
     std::mem::swap(&mut state, &mut signed_channel.state);
@@ -2303,12 +2305,18 @@ pub fn accept_collaborative_close_offer<C: Signing, S: Deref>(
 where
     S::Target: Signer,
 {
-    let (offer_signature, close_tx) = get_signed_channel_state!(
+    let (offer_signature, close_tx, is_offer) = get_signed_channel_state!(
         signed_channel,
         CollaborativeCloseOffered,
-        offer_signature | close_tx
+        offer_signature | close_tx, is_offer
     )?;
 
+    if *is_offer {
+        return Err(Error::InvalidState(
+            "Cannot accept own collaborative close offer".to_string(),
+        ));
+    }
+
     let fund_out_amount = signed_channel.fund_tx.output[signed_channel.fund_output_index].value;
 
     let own_fund_sk = signer.get_secret_key_for_pubkey(&signed_channel.own_params.fund_pubkey)?;

dlc-manager/tests/channel_execution_tests.rs

@@ -91,7 +91,9 @@ enum TestPath {
     BufferCheat,
     RenewedClose,
     SettleCheat,
-    CollaborativeClose,
+    CollaborativeClose{
+        accept_own_offer: bool
+    },
     SettleRenewSettle,
     SettleOfferTimeout,
     SettleAcceptTimeout,
@@ -170,7 +172,16 @@ fn channel_settle_cheat_test() {
 fn channel_collaborative_close_test() {
     channel_execution_test(
         get_enum_test_params(1, 1, None),
-        TestPath::CollaborativeClose,
+        TestPath::CollaborativeClose{ accept_own_offer: false},
+    );
+}
+
+#[test]
+#[ignore]
+fn channel_collaborative_close_own_offer_test() {
+    channel_execution_test(
+        get_enum_test_params(1, 1, None),
+        TestPath::CollaborativeClose{ accept_own_offer: true},
     );
 }
 
@@ -578,14 +589,15 @@ fn channel_execution_test(test_params: TestParams, path: TestPath) {
                 TestPath::Close => {
                     close_established_channel(first, second, channel_id, &generate_blocks);
                 }
-                TestPath::CollaborativeClose => {
+                TestPath::CollaborativeClose { accept_own_offer } => {
                     collaborative_close(
                         first,
                         first_send,
                         second,
                         channel_id,
                         second_receive,
                         &generate_blocks,
+                        accept_own_offer
                     );
                 }
                 TestPath::SettleOfferTimeout
@@ -1204,6 +1216,7 @@ fn collaborative_close<F: Fn(u64)>(
     channel_id: DlcChannelId,
     sync_receive: &Receiver<()>,
     generate_blocks: &F,
+    accept_own_offer: bool
 ) {
     let contract_id = get_established_channel_contract_id(&first, &channel_id);
     let close_offer = first
@@ -1221,6 +1234,17 @@ fn collaborative_close<F: Fn(u64)>(
     assert_channel_state!(first, channel_id, Signed, CollaborativeCloseOffered);
     assert_channel_state!(second, channel_id, Signed, CollaborativeCloseOffered);
 
+    if accept_own_offer {
+        if let Err(e) = first.lock().unwrap().accept_collaborative_close(&channel_id) {
+            assert_eq!("Invalid state: Cannot accept own collaborative close offer", e.to_string());
+        } else {
+            panic!("It should not be possible to accept own collaborative close offer");
+        }
+
+        return;
+    }
+
+
     second
         .lock()
         .unwrap()