Expose required features APIs for init message

Add requires_* counterparts for every supports_* method
on InitFeatures, completing the BOLT 9 feature flag
coverage for FFI consumers.

Author: enigbe

src/ffi/types.rs

@@ -1546,6 +1546,14 @@ impl InitFeatures {
 		self.inner.supports_static_remote_key()
 	}
 
+	/// Whether the peer requires `option_static_remotekey` (bit 12).
+	///
+	/// This ensures the non-broadcaster's output pays directly to their specified key,
+	/// simplifying recovery if a channel is force-closed.
+	pub fn requires_static_remote_key(&self) -> bool {
+		self.inner.requires_static_remote_key()
+	}
+
 	/// Whether the peer supports `option_anchors_zero_fee_htlc_tx` (bit 23).
 	///
 	/// Anchor channels allow fee-bumping commitment transactions after broadcast,
@@ -1554,6 +1562,14 @@ impl InitFeatures {
 		self.inner.supports_anchors_zero_fee_htlc_tx()
 	}
 
+	/// Whether the peer requires `option_anchors_zero_fee_htlc_tx` (bit 22).
+	///
+	/// Anchor channels allow fee-bumping commitment transactions after broadcast,
+	/// improving on-chain fee management.
+	pub fn requires_anchors_zero_fee_htlc_tx(&self) -> bool {
+		self.inner.requires_anchors_zero_fee_htlc_tx()
+	}
+
 	/// Whether the peer supports `option_anchors_nonzero_fee_htlc_tx` (bit 21).
 	///
 	/// The initial version of anchor outputs, which was later found to be
@@ -1562,13 +1578,29 @@ impl InitFeatures {
 		self.inner.supports_anchors_nonzero_fee_htlc_tx()
 	}
 
+	/// Whether the peer requires `option_anchors_nonzero_fee_htlc_tx` (bit 20).
+	///
+	/// The initial version of anchor outputs, which was later found to be
+	/// vulnerable and superseded by `option_anchors_zero_fee_htlc_tx`.
+	pub fn requires_anchors_nonzero_fee_htlc_tx(&self) -> bool {
+		self.inner.requires_anchors_nonzero_fee_htlc_tx()
+	}
+
 	/// Whether the peer supports `option_support_large_channel` (bit 19).
 	///
 	/// When supported, channels larger than 2^24 satoshis (≈0.168 BTC) may be opened.
 	pub fn supports_wumbo(&self) -> bool {
 		self.inner.supports_wumbo()
 	}
 
+	/// Whether the peer requires `option_support_large_channel` (bit 18).
+	///
+	/// When required, the peer will only connect to nodes that support
+	/// channels larger than 2^24 satoshis (≈0.168 BTC).
+	pub fn requires_wumbo(&self) -> bool {
+		self.inner.requires_wumbo()
+	}
+
 	/// Whether the peer supports `option_route_blinding` (bit 25).
 	///
 	/// Route blinding allows the recipient to hide their node identity and
@@ -1577,6 +1609,14 @@ impl InitFeatures {
 		self.inner.supports_route_blinding()
 	}
 
+	/// Whether the peer requires `option_route_blinding` (bit 24).
+	///
+	/// Route blinding allows the recipient to hide their node identity and
+	/// last-hop channel from the sender.
+	pub fn requires_route_blinding(&self) -> bool {
+		self.inner.requires_route_blinding()
+	}
+
 	/// Whether the peer supports `option_onion_messages` (bit 39).
 	///
 	/// Onion messages enable communication over the Lightning Network without
@@ -1585,6 +1625,14 @@ impl InitFeatures {
 		self.inner.supports_onion_messages()
 	}
 
+	/// Whether the peer requires `option_onion_messages` (bit 38).
+	///
+	/// Onion messages enable communication over the Lightning Network without
+	/// requiring a payment, used by BOLT 12 offers and async payments.
+	pub fn requires_onion_messages(&self) -> bool {
+		self.inner.requires_onion_messages()
+	}
+
 	/// Whether the peer supports `option_scid_alias` (bit 47).
 	///
 	/// When supported, the peer will only forward using short channel ID aliases,
@@ -1593,6 +1641,14 @@ impl InitFeatures {
 		self.inner.supports_scid_privacy()
 	}
 
+	/// Whether the peer supports `option_scid_alias` (bit 46).
+	///
+	/// When required, the peer will only forward using short channel ID aliases,
+	/// preventing the real channel UTXO from being revealed during routing.
+	pub fn requires_scid_privacy(&self) -> bool {
+		self.inner.requires_scid_privacy()
+	}
+
 	/// Whether the peer supports `option_zeroconf` (bit 51).
 	///
 	/// Zero-conf channels can be used immediately without waiting for
@@ -1601,6 +1657,14 @@ impl InitFeatures {
 		self.inner.supports_zero_conf()
 	}
 
+	/// Whether the peer requires `option_zeroconf` (bit 50).
+	///
+	/// Zero-conf channels can be used immediately without waiting for
+	/// on-chain funding confirmations.
+	pub fn requires_zero_conf(&self) -> bool {
+		self.inner.requires_zero_conf()
+	}
+
 	/// Whether the peer supports `option_dual_fund` (bit 29).
 	///
 	/// Dual-funded channels allow both parties to contribute funds
@@ -1609,6 +1673,14 @@ impl InitFeatures {
 		self.inner.supports_dual_fund()
 	}
 
+	/// Whether the peer requires `option_dual_fund` (bit 28).
+	///
+	/// Dual-funded channels allow both parties to contribute funds
+	/// to the channel opening transaction.
+	pub fn requires_dual_fund(&self) -> bool {
+		self.inner.requires_dual_fund()
+	}
+
 	/// Whether the peer supports `option_quiesce` (bit 35).
 	///
 	/// Quiescence is a prerequisite for splicing, allowing both sides to
@@ -1617,6 +1689,14 @@ impl InitFeatures {
 		self.inner.supports_quiescence()
 	}
 
+	/// Whether the peer requires `option_quiesce` (bit 34).
+	///
+	/// Quiescence is a prerequisite for splicing, allowing both sides to
+	/// pause HTLC activity before modifying the funding transaction.
+	pub fn requires_quiescence(&self) -> bool {
+		self.inner.requires_quiescence()
+	}
+
 	/// Whether the peer supports `option_data_loss_protect` (bit 1).
 	///
 	/// Allows a node that has fallen behind (e.g., restored from backup)
@@ -1625,6 +1705,14 @@ impl InitFeatures {
 		self.inner.supports_data_loss_protect()
 	}
 
+	/// Whether the peer requires `option_data_loss_protect` (bit 0).
+	///
+	/// Allows a node that has fallen behind (e.g., restored from backup)
+	/// to detect that it is out of date and close the channel safely.
+	pub fn requires_data_loss_protect(&self) -> bool {
+		self.inner.requires_data_loss_protect()
+	}
+
 	/// Whether the peer supports `option_upfront_shutdown_script` (bit 5).
 	///
 	/// Commits to a shutdown scriptpubkey when opening a channel,
@@ -1633,6 +1721,14 @@ impl InitFeatures {
 		self.inner.supports_upfront_shutdown_script()
 	}
 
+	/// Whether the peer requires `option_upfront_shutdown_script` (bit 4).
+	///
+	/// Commits to a shutdown scriptpubkey when opening a channel,
+	/// preventing a compromised key from redirecting closing funds.
+	pub fn requires_upfront_shutdown_script(&self) -> bool {
+		self.inner.requires_upfront_shutdown_script()
+	}
+
 	/// Whether the peer supports `gossip_queries` (bit 7).
 	///
 	/// Indicates the peer has useful gossip to share and supports
@@ -1641,14 +1737,30 @@ impl InitFeatures {
 		self.inner.supports_gossip_queries()
 	}
 
+	/// Whether the peer requires `gossip_queries` (bit 6).
+	///
+	/// Indicates the peer has useful gossip to share and supports
+	/// gossip query messages for synchronization.
+	pub fn requires_gossip_queries(&self) -> bool {
+		self.inner.requires_gossip_queries()
+	}
+
 	/// Whether the peer supports `var_onion_optin` (bit 9).
 	///
-	/// Requires variable-length routing onion payloads, which is
-	/// assumed to be supported by all modern Lightning nodes.
+	/// Supports variable-length routing onion payloads, which is
+	/// assumed to be supported and required by all modern Lightning nodes.
 	pub fn supports_variable_length_onion(&self) -> bool {
 		self.inner.supports_variable_length_onion()
 	}
 
+	/// Whether the peer requires `var_onion_optin` (bit 8).
+	///
+	/// Requires variable-length routing onion payloads, which is
+	/// assumed to be supported and required by all modern Lightning nodes.
+	pub fn requires_variable_length_onion(&self) -> bool {
+		self.inner.requires_variable_length_onion()
+	}
+
 	/// Whether the peer supports `payment_secret` (bit 15).
 	///
 	/// Payment secrets prevent forwarding nodes from probing
@@ -1657,6 +1769,14 @@ impl InitFeatures {
 		self.inner.supports_payment_secret()
 	}
 
+	/// Whether the peer requires `payment_secret` (bit 14).
+	///
+	/// Payment secrets prevent forwarding nodes from probing
+	/// payment recipients. Assumed to be supported by all modern nodes.
+	pub fn requires_payment_secret(&self) -> bool {
+		self.inner.requires_payment_secret()
+	}
+
 	/// Whether the peer supports `basic_mpp` (bit 17).
 	///
 	/// Multi-part payments allow splitting a payment across multiple
@@ -1665,6 +1785,14 @@ impl InitFeatures {
 		self.inner.supports_basic_mpp()
 	}
 
+	/// Whether the peer requires `basic_mpp` (bit 16).
+	///
+	/// Multi-part payments allow splitting a payment across multiple
+	/// routes for improved reliability and liquidity utilization.
+	pub fn requires_basic_mpp(&self) -> bool {
+		self.inner.requires_basic_mpp()
+	}
+
 	/// Whether the peer supports `opt_shutdown_anysegwit` (bit 27).
 	///
 	/// Allows future segwit versions in the shutdown script,
@@ -1673,13 +1801,28 @@ impl InitFeatures {
 		self.inner.supports_shutdown_anysegwit()
 	}
 
+	/// Whether the peer requires `opt_shutdown_anysegwit` (bit 26).
+	///
+	/// Allows future segwit versions in the shutdown script,
+	/// enabling closing to Taproot or later output types.
+	pub fn requires_shutdown_anysegwit(&self) -> bool {
+		self.inner.requires_shutdown_anysegwit()
+	}
+
 	/// Whether the peer supports `option_channel_type` (bit 45).
 	///
 	/// Supports explicit channel type negotiation during channel opening.
 	pub fn supports_channel_type(&self) -> bool {
 		self.inner.supports_channel_type()
 	}
 
+	/// Whether the peer requires `option_channel_type` (bit 44).
+	///
+	/// Requires explicit channel type negotiation during channel opening.
+	pub fn requires_channel_type(&self) -> bool {
+		self.inner.requires_channel_type()
+	}
+
 	/// Whether the peer supports `option_trampoline` (bit 57).
 	///
 	/// Trampoline routing allows lightweight nodes to delegate
@@ -1688,6 +1831,14 @@ impl InitFeatures {
 		self.inner.supports_trampoline_routing()
 	}
 
+	/// Whether the peer requires `option_trampoline` (bit 56).
+	///
+	/// Trampoline routing allows lightweight nodes to delegate
+	/// pathfinding to an intermediate trampoline node.
+	pub fn requires_trampoline_routing(&self) -> bool {
+		self.inner.requires_trampoline_routing()
+	}
+
 	/// Whether the peer supports `option_simple_close` (bit 61).
 	///
 	/// Simplified closing negotiation reduces the number of
@@ -1696,6 +1847,14 @@ impl InitFeatures {
 		self.inner.supports_simple_close()
 	}
 
+	/// Whether the peer requires `option_simple_close` (bit 60).
+	///
+	/// Simplified closing negotiation reduces the number of
+	/// round trips needed for a cooperative channel close.
+	pub fn requires_simple_close(&self) -> bool {
+		self.inner.requires_simple_close()
+	}
+
 	/// Whether the peer supports `option_splice` (bit 63).
 	///
 	/// Splicing allows replacing the funding transaction with a new one,
@@ -1704,6 +1863,14 @@ impl InitFeatures {
 		self.inner.supports_splicing()
 	}
 
+	/// Whether the peer requires `option_splice` (bit 62).
+	///
+	/// Splicing allows replacing the funding transaction with a new one,
+	/// enabling on-the-fly capacity changes without closing the channel.
+	pub fn requires_splicing(&self) -> bool {
+		self.inner.requires_splicing()
+	}
+
 	/// Whether the peer supports `option_provide_storage` (bit 43).
 	///
 	/// Indicates the node offers to store encrypted backup data
@@ -1712,6 +1879,14 @@ impl InitFeatures {
 		self.inner.supports_provide_storage()
 	}
 
+	/// Whether the peer requires `option_provide_storage` (bit 42).
+	///
+	/// Indicates the node offers to store encrypted backup data
+	/// on behalf of its peers.
+	pub fn requires_provide_storage(&self) -> bool {
+		self.inner.requires_provide_storage()
+	}
+
 	/// Whether the peer set `initial_routing_sync` (bit 3).
 	///
 	/// Indicates the sending node needs a complete routing information dump.
@@ -1728,6 +1903,14 @@ impl InitFeatures {
 		self.inner.supports_taproot()
 	}
 
+	/// Whether the peer requires `option_taproot` (bit 30).
+	///
+	/// Taproot channels use MuSig2-based multisig for funding outputs,
+	/// improving privacy and efficiency.
+	pub fn requires_taproot(&self) -> bool {
+		self.inner.requires_taproot()
+	}
+
 	/// Whether the peer supports `option_zero_fee_commitments` (bit 141, experimental).
 	///
 	/// A channel type which always uses zero transaction fee on commitment
@@ -1736,12 +1919,27 @@ impl InitFeatures {
 		self.inner.supports_anchor_zero_fee_commitments()
 	}
 
+	/// Whether the peer requires `option_zero_fee_commitments` (bit 140, experimental).
+	///
+	/// A channel type which always uses zero transaction fee on commitment
+	/// transactions, combined with anchor outputs.
+	pub fn requires_anchor_zero_fee_commitments(&self) -> bool {
+		self.inner.requires_anchor_zero_fee_commitments()
+	}
+
 	/// Whether the peer supports HTLC hold (bit 153, experimental).
 	///
 	/// Supports holding HTLCs and forwarding on receipt of an onion message.
 	pub fn supports_htlc_hold(&self) -> bool {
 		self.inner.supports_htlc_hold()
 	}
+
+	/// Whether the peer requires HTLC hold (bit 152, experimental).
+	///
+	/// Requires holding HTLCs and forwarding on receipt of an onion message.
+	pub fn requires_htlc_hold(&self) -> bool {
+		self.inner.requires_htlc_hold()
+	}
 }
 
 impl From<LdkInitFeatures> for InitFeatures {