use crate::ln::channelmanager::{ChannelDetails, PaymentId};
use crate::ln::features::{Bolt12InvoiceFeatures, ChannelFeatures, InvoiceFeatures, NodeFeatures};
use crate::ln::msgs::{DecodeError, ErrorAction, LightningError, MAX_VALUE_MSAT};
-use crate::offers::invoice::BlindedPayInfo;
+use crate::offers::invoice::{BlindedPayInfo, Invoice as Bolt12Invoice};
use crate::routing::gossip::{DirectedChannelInfo, EffectiveCapacity, ReadOnlyNetworkGraph, NetworkGraph, NodeId, RoutingFees};
use crate::routing::scoring::{ChannelUsage, LockableScore, Score};
use crate::util::ser::{Writeable, Readable, ReadableArgs, Writer};
// limits, but for now more than 10 paths likely carries too much one-path failure.
pub const DEFAULT_MAX_PATH_COUNT: u8 = 10;
+const DEFAULT_MAX_CHANNEL_SATURATION_POW_HALF: u8 = 2;
+
// The median hop CLTV expiry delta currently seen in the network.
const MEDIAN_HOP_CLTV_EXPIRY_DELTA: u32 = 40;
(2, features, (option: ReadableArgs, payee_pubkey.is_some())),
(3, max_path_count, (default_value, DEFAULT_MAX_PATH_COUNT)),
(4, route_hints, vec_type),
- (5, max_channel_saturation_power_of_half, (default_value, 2)),
+ (5, max_channel_saturation_power_of_half, (default_value, DEFAULT_MAX_CHANNEL_SATURATION_POW_HALF)),
(6, expiry_time, option),
(7, previously_failed_channels, vec_type),
(8, blinded_route_hints, optional_vec),
expiry_time: None,
max_total_cltv_expiry_delta: DEFAULT_MAX_TOTAL_CLTV_EXPIRY_DELTA,
max_path_count: DEFAULT_MAX_PATH_COUNT,
- max_channel_saturation_power_of_half: 2,
+ max_channel_saturation_power_of_half: DEFAULT_MAX_CHANNEL_SATURATION_POW_HALF,
previously_failed_channels: Vec::new(),
}
}
.expect("PaymentParameters::from_node_id should always initialize the payee as unblinded")
}
- /// Includes the payee's features. Errors if the parameters were initialized with blinded payment
- /// paths.
+ /// Creates parameters for paying to a blinded payee from the provided invoice. Sets
+ /// [`Payee::Blinded::route_hints`], [`Payee::Blinded::features`], and
+ /// [`PaymentParameters::expiry_time`].
+ pub fn from_bolt12_invoice(invoice: &Bolt12Invoice) -> Self {
+ Self::blinded(invoice.payment_paths().to_vec())
+ .with_bolt12_features(invoice.features().clone()).unwrap()
+ .with_expiry_time(invoice.created_at().as_secs().saturating_add(invoice.relative_expiry().as_secs()))
+ }
+
+ fn blinded(blinded_route_hints: Vec<(BlindedPayInfo, BlindedPath)>) -> Self {
+ Self {
+ payee: Payee::Blinded { route_hints: blinded_route_hints, features: None },
+ expiry_time: None,
+ max_total_cltv_expiry_delta: DEFAULT_MAX_TOTAL_CLTV_EXPIRY_DELTA,
+ max_path_count: DEFAULT_MAX_PATH_COUNT,
+ max_channel_saturation_power_of_half: DEFAULT_MAX_CHANNEL_SATURATION_POW_HALF,
+ previously_failed_channels: Vec::new(),
+ }
+ }
+
+ /// Includes the payee's features. Errors if the parameters were not initialized with
+ /// [`PaymentParameters::from_bolt12_invoice`].
+ ///
+ /// This is not exported to bindings users since bindings don't support move semantics
+ pub fn with_bolt12_features(self, features: Bolt12InvoiceFeatures) -> Result<Self, ()> {
+ match self.payee {
+ Payee::Clear { .. } => Err(()),
+ Payee::Blinded { route_hints, .. } =>
+ Ok(Self { payee: Payee::Blinded { route_hints, features: Some(features) }, ..self })
+ }
+ }
+
+ /// Includes the payee's features. Errors if the parameters were initialized with
+ /// [`PaymentParameters::from_bolt12_invoice`].
///
/// This is not exported to bindings users since bindings don't support move semantics
pub fn with_bolt11_features(self, features: InvoiceFeatures) -> Result<Self, ()> {
}
/// Includes hints for routing to the payee. Errors if the parameters were initialized with
- /// blinded payment paths.
+ /// [`PaymentParameters::from_bolt12_invoice`].
///
/// This is not exported to bindings users since bindings don't support move semantics
pub fn with_route_hints(self, route_hints: Vec<RouteHint>) -> Result<Self, ()> {
Self { max_path_count, ..self }
}
- /// Includes a limit for the maximum number of payment paths that may be used.
+ /// Includes a limit for the maximum share of a channel's total capacity that can be sent over, as
+ /// a power of 1/2. See [`PaymentParameters::max_channel_saturation_power_of_half`].
///
/// This is not exported to bindings users since bindings don't support move semantics
pub fn with_max_channel_saturation_power_of_half(self, max_channel_saturation_power_of_half: u8) -> Self {
_ => None,
}
}
+ fn blinded_route_hints(&self) -> &[(BlindedPayInfo, BlindedPath)] {
+ match self {
+ Self::Blinded { route_hints, .. } => &route_hints[..],
+ Self::Clear { .. } => &[]
+ }
+ }
+
+ fn unblinded_route_hints(&self) -> &[RouteHint] {
+ match self {
+ Self::Blinded { .. } => &[],
+ Self::Clear { route_hints, .. } => &route_hints[..]
+ }
+ }
}
enum FeaturesRef<'a> {
info: DirectedChannelInfo<'a>,
short_channel_id: u64,
},
- /// A hop to the payee found in the payment invoice, though not necessarily a direct channel.
+ /// A hop to the payee found in the BOLT 11 payment invoice, though not necessarily a direct
+ /// channel.
PrivateHop {
hint: &'a RouteHintHop,
- }
+ },
+ /// The payee's identity is concealed behind blinded paths provided in a BOLT 12 invoice.
+ Blinded {
+ hint: &'a (BlindedPayInfo, BlindedPath),
+ hint_idx: usize,
+ },
+ /// Similar to [`Self::Blinded`], but the path here has 1 blinded hop. `BlindedPayInfo` provided
+ /// for 1-hop blinded paths is ignored because it is meant to apply to the hops *between* the
+ /// introduction node and the destination. Useful for tracking that we need to include a blinded
+ /// path at the end of our [`Route`].
+ OneHopBlinded {
+ hint: &'a (BlindedPayInfo, BlindedPath),
+ hint_idx: usize,
+ },
}
impl<'a> CandidateRouteHop<'a> {
- fn short_channel_id(&self) -> u64 {
+ fn short_channel_id(&self) -> Option<u64> {
match self {
- CandidateRouteHop::FirstHop { details } => details.get_outbound_payment_scid().unwrap(),
- CandidateRouteHop::PublicHop { short_channel_id, .. } => *short_channel_id,
- CandidateRouteHop::PrivateHop { hint } => hint.short_channel_id,
+ CandidateRouteHop::FirstHop { details } => Some(details.get_outbound_payment_scid().unwrap()),
+ CandidateRouteHop::PublicHop { short_channel_id, .. } => Some(*short_channel_id),
+ CandidateRouteHop::PrivateHop { hint } => Some(hint.short_channel_id),
+ CandidateRouteHop::Blinded { .. } => None,
+ CandidateRouteHop::OneHopBlinded { .. } => None,
}
}
CandidateRouteHop::FirstHop { details } => details.counterparty.features.to_context(),
CandidateRouteHop::PublicHop { info, .. } => info.channel().features.clone(),
CandidateRouteHop::PrivateHop { .. } => ChannelFeatures::empty(),
+ CandidateRouteHop::Blinded { .. } => ChannelFeatures::empty(),
+ CandidateRouteHop::OneHopBlinded { .. } => ChannelFeatures::empty(),
}
}
CandidateRouteHop::FirstHop { .. } => 0,
CandidateRouteHop::PublicHop { info, .. } => info.direction().cltv_expiry_delta as u32,
CandidateRouteHop::PrivateHop { hint } => hint.cltv_expiry_delta as u32,
+ CandidateRouteHop::Blinded { hint, .. } => hint.0.cltv_expiry_delta as u32,
+ CandidateRouteHop::OneHopBlinded { .. } => 0,
}
}
CandidateRouteHop::FirstHop { details } => details.next_outbound_htlc_minimum_msat,
CandidateRouteHop::PublicHop { info, .. } => info.direction().htlc_minimum_msat,
CandidateRouteHop::PrivateHop { hint } => hint.htlc_minimum_msat.unwrap_or(0),
+ CandidateRouteHop::Blinded { hint, .. } => hint.0.htlc_minimum_msat,
+ CandidateRouteHop::OneHopBlinded { .. } => 0,
}
}
},
CandidateRouteHop::PublicHop { info, .. } => info.direction().fees,
CandidateRouteHop::PrivateHop { hint } => hint.fees,
+ CandidateRouteHop::Blinded { hint, .. } => {
+ RoutingFees {
+ base_msat: hint.0.fee_base_msat,
+ proportional_millionths: hint.0.fee_proportional_millionths
+ }
+ },
+ CandidateRouteHop::OneHopBlinded { .. } =>
+ RoutingFees { base_msat: 0, proportional_millionths: 0 },
}
}
EffectiveCapacity::HintMaxHTLC { amount_msat: *max },
CandidateRouteHop::PrivateHop { hint: RouteHintHop { htlc_maximum_msat: None, .. }} =>
EffectiveCapacity::Infinite,
+ CandidateRouteHop::Blinded { hint, .. } =>
+ EffectiveCapacity::HintMaxHTLC { amount_msat: hint.0.htlc_maximum_msat },
+ CandidateRouteHop::OneHopBlinded { .. } => EffectiveCapacity::Infinite,
+ }
+ }
+
+ fn id(&self, channel_direction: bool /* src_node_id < target_node_id */) -> CandidateHopId {
+ match self {
+ CandidateRouteHop::Blinded { hint_idx, .. } => CandidateHopId::Blinded(*hint_idx),
+ CandidateRouteHop::OneHopBlinded { hint_idx, .. } => CandidateHopId::Blinded(*hint_idx),
+ _ => CandidateHopId::Clear((self.short_channel_id().unwrap(), channel_direction)),
}
}
+ fn blinded_path(&self) -> Option<&'a BlindedPath> {
+ match self {
+ CandidateRouteHop::Blinded { hint, .. } | CandidateRouteHop::OneHopBlinded { hint, .. } => {
+ Some(&hint.1)
+ },
+ _ => None,
+ }
+ }
+}
+
+#[derive(Clone, Copy, Eq, Hash, Ord, PartialOrd, PartialEq)]
+enum CandidateHopId {
+ /// Contains (scid, src_node_id < target_node_id)
+ Clear((u64, bool)),
+ /// Index of the blinded route hint in [`Payee::Blinded::route_hints`].
+ Blinded(usize),
}
#[inline]
}
}
+struct LoggedCandidateHop<'a>(&'a CandidateRouteHop<'a>);
+impl<'a> fmt::Display for LoggedCandidateHop<'a> {
+ fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+ match self.0 {
+ CandidateRouteHop::Blinded { hint, .. } | CandidateRouteHop::OneHopBlinded { hint, .. } => {
+ "blinded route hint with introduction node id ".fmt(f)?;
+ hint.1.introduction_node_id.fmt(f)?;
+ " and blinding point ".fmt(f)?;
+ hint.1.blinding_point.fmt(f)
+ },
+ _ => {
+ "SCID ".fmt(f)?;
+ self.0.short_channel_id().unwrap().fmt(f)
+ },
+ }
+ }
+}
+
#[inline]
fn sort_first_hop_channels(
- channels: &mut Vec<&ChannelDetails>, used_channel_liquidities: &HashMap<(u64, bool), u64>,
+ channels: &mut Vec<&ChannelDetails>, used_liquidities: &HashMap<CandidateHopId, u64>,
recommended_value_msat: u64, our_node_pubkey: &PublicKey
) {
// Sort the first_hops channels to the same node(s) in priority order of which channel we'd
// Available outbound balances factor in liquidity already reserved for previously found paths.
channels.sort_unstable_by(|chan_a, chan_b| {
let chan_a_outbound_limit_msat = chan_a.next_outbound_htlc_limit_msat
- .saturating_sub(*used_channel_liquidities.get(&(chan_a.get_outbound_payment_scid().unwrap(),
- our_node_pubkey < &chan_a.counterparty.node_id)).unwrap_or(&0));
+ .saturating_sub(*used_liquidities.get(&CandidateHopId::Clear((chan_a.get_outbound_payment_scid().unwrap(),
+ our_node_pubkey < &chan_a.counterparty.node_id))).unwrap_or(&0));
let chan_b_outbound_limit_msat = chan_b.next_outbound_htlc_limit_msat
- .saturating_sub(*used_channel_liquidities.get(&(chan_b.get_outbound_payment_scid().unwrap(),
- our_node_pubkey < &chan_b.counterparty.node_id)).unwrap_or(&0));
+ .saturating_sub(*used_liquidities.get(&CandidateHopId::Clear((chan_b.get_outbound_payment_scid().unwrap(),
+ our_node_pubkey < &chan_b.counterparty.node_id))).unwrap_or(&0));
if chan_b_outbound_limit_msat < recommended_value_msat || chan_a_outbound_limit_msat < recommended_value_msat {
// Sort in descending order
chan_b_outbound_limit_msat.cmp(&chan_a_outbound_limit_msat)
// unblinded payee id as an option. We also need a non-optional "payee id" for path construction,
// so use a dummy id for this in the blinded case.
let payee_node_id_opt = payment_params.payee.node_id().map(|pk| NodeId::from_pubkey(&pk));
- const DUMMY_BLINDED_PAYEE_ID: [u8; 33] = [42u8; 33];
+ const DUMMY_BLINDED_PAYEE_ID: [u8; 33] = [2; 33];
let maybe_dummy_payee_pk = payment_params.payee.node_id().unwrap_or_else(|| PublicKey::from_slice(&DUMMY_BLINDED_PAYEE_ID).unwrap());
let maybe_dummy_payee_node_id = NodeId::from_pubkey(&maybe_dummy_payee_pk);
let our_node_id = NodeId::from_pubkey(&our_node_pubkey);
}
}
},
- _ => return Err(LightningError{err: "Routing to blinded paths isn't supported yet".to_owned(), action: ErrorAction::IgnoreError}),
-
+ Payee::Blinded { route_hints, .. } => {
+ if route_hints.iter().all(|(_, path)| &path.introduction_node_id == our_node_pubkey) {
+ return Err(LightningError{err: "Cannot generate a route to blinded paths if we are the introduction node to all of them".to_owned(), action: ErrorAction::IgnoreError});
+ }
+ for (_, blinded_path) in route_hints.iter() {
+ if blinded_path.blinded_hops.len() == 0 {
+ return Err(LightningError{err: "0-hop blinded path provided".to_owned(), action: ErrorAction::IgnoreError});
+ } else if &blinded_path.introduction_node_id == our_node_pubkey {
+ log_info!(logger, "Got blinded path with ourselves as the introduction node, ignoring");
+ } else if blinded_path.blinded_hops.len() == 1 &&
+ route_hints.iter().any( |(_, p)| p.blinded_hops.len() == 1
+ && p.introduction_node_id != blinded_path.introduction_node_id)
+ {
+ return Err(LightningError{err: format!("1-hop blinded paths must all have matching introduction node ids"), action: ErrorAction::IgnoreError});
+ }
+ }
+ }
}
let final_cltv_expiry_delta = payment_params.payee.final_cltv_expiry_delta().unwrap_or(0);
if payment_params.max_total_cltv_expiry_delta <= final_cltv_expiry_delta {
// drop the requirement by setting this to 0.
let mut channel_saturation_pow_half = payment_params.max_channel_saturation_power_of_half;
- // Keep track of how much liquidity has been used in selected channels. Used to determine
- // if the channel can be used by additional MPP paths or to inform path finding decisions. It is
- // aware of direction *only* to ensure that the correct htlc_maximum_msat value is used. Hence,
- // liquidity used in one direction will not offset any used in the opposite direction.
- let mut used_channel_liquidities: HashMap<(u64, bool), u64> =
+ // Keep track of how much liquidity has been used in selected channels or blinded paths. Used to
+ // determine if the channel can be used by additional MPP paths or to inform path finding
+ // decisions. It is aware of direction *only* to ensure that the correct htlc_maximum_msat value
+ // is used. Hence, liquidity used in one direction will not offset any used in the opposite
+ // direction.
+ let mut used_liquidities: HashMap<CandidateHopId, u64> =
HashMap::with_capacity(network_nodes.len());
// Keeping track of how much value we already collected across other paths. Helps to decide
let mut already_collected_value_msat = 0;
for (_, channels) in first_hop_targets.iter_mut() {
- sort_first_hop_channels(channels, &used_channel_liquidities, recommended_value_msat,
+ sort_first_hop_channels(channels, &used_liquidities, recommended_value_msat,
our_node_pubkey);
}
// - for regular channels at channel announcement (TODO)
// - for first and last hops early in get_route
if $src_node_id != $dest_node_id {
- let short_channel_id = $candidate.short_channel_id();
+ let scid_opt = $candidate.short_channel_id();
let effective_capacity = $candidate.effective_capacity();
let htlc_maximum_msat = max_htlc_from_capacity(effective_capacity, channel_saturation_pow_half);
// if the amount being transferred over this path is lower.
// We do this for now, but this is a subject for removal.
if let Some(mut available_value_contribution_msat) = htlc_maximum_msat.checked_sub($next_hops_fee_msat) {
- let used_liquidity_msat = used_channel_liquidities
- .get(&(short_channel_id, $src_node_id < $dest_node_id))
+ let used_liquidity_msat = used_liquidities
+ .get(&$candidate.id($src_node_id < $dest_node_id))
.map_or(0, |used_liquidity_msat| {
available_value_contribution_msat = available_value_contribution_msat
.saturating_sub(*used_liquidity_msat);
(amount_to_transfer_over_msat < $next_hops_path_htlc_minimum_msat &&
recommended_value_msat > $next_hops_path_htlc_minimum_msat));
- let payment_failed_on_this_channel =
- payment_params.previously_failed_channels.contains(&short_channel_id);
+ let payment_failed_on_this_channel = scid_opt.map_or(false,
+ |scid| payment_params.previously_failed_channels.contains(&scid));
// If HTLC minimum is larger than the amount we're going to transfer, we shouldn't
// bother considering this channel. If retrying with recommended_value_msat may
inflight_htlc_msat: used_liquidity_msat,
effective_capacity,
};
- let channel_penalty_msat = scorer.channel_penalty_msat(
- short_channel_id, &$src_node_id, &$dest_node_id, channel_usage, score_params
- );
+ let channel_penalty_msat = scid_opt.map_or(0,
+ |scid| scorer.channel_penalty_msat(scid, &$src_node_id, &$dest_node_id,
+ channel_usage, score_params));
let path_penalty_msat = $next_hops_path_penalty_msat
.saturating_add(channel_penalty_msat);
let new_graph_node = RouteGraphNode {
// TODO: diversify by nodes (so that all paths aren't doomed if one node is offline).
'paths_collection: loop {
- // For every new path, start from scratch, except for used_channel_liquidities, which
+ // For every new path, start from scratch, except for used_liquidities, which
// helps to avoid reusing previously selected paths in future iterations.
targets.clear();
dist.clear();
let candidate = CandidateRouteHop::FirstHop { details };
let added = add_entry!(candidate, our_node_id, payee, 0, path_value_msat,
0, 0u64, 0, 0).is_some();
- log_trace!(logger, "{} direct route to payee via SCID {}",
- if added { "Added" } else { "Skipped" }, candidate.short_channel_id());
+ log_trace!(logger, "{} direct route to payee via {}",
+ if added { "Added" } else { "Skipped" }, LoggedCandidateHop(&candidate));
}
}));
// If a caller provided us with last hops, add them to routing targets. Since this happens
// earlier than general path finding, they will be somewhat prioritized, although currently
// it matters only if the fees are exactly the same.
- let route_hints = match &payment_params.payee {
- Payee::Clear { route_hints, .. } => route_hints,
- _ => return Err(LightningError{err: "Routing to blinded paths isn't supported yet".to_owned(), action: ErrorAction::IgnoreError}),
- };
- for route in route_hints.iter().filter(|route| !route.0.is_empty()) {
+ for (hint_idx, hint) in payment_params.payee.blinded_route_hints().iter().enumerate() {
+ let intro_node_id = NodeId::from_pubkey(&hint.1.introduction_node_id);
+ let have_intro_node_in_graph =
+ // Only add the hops in this route to our candidate set if either
+ // we have a direct channel to the first hop or the first hop is
+ // in the regular network graph.
+ first_hop_targets.get(&intro_node_id).is_some() ||
+ network_nodes.get(&intro_node_id).is_some();
+ if !have_intro_node_in_graph { continue }
+ let candidate = if hint.1.blinded_hops.len() == 1 {
+ CandidateRouteHop::OneHopBlinded { hint, hint_idx }
+ } else { CandidateRouteHop::Blinded { hint, hint_idx } };
+ let mut path_contribution_msat = path_value_msat;
+ if let Some(hop_used_msat) = add_entry!(candidate, intro_node_id, maybe_dummy_payee_node_id,
+ 0, path_contribution_msat, 0, 0_u64, 0, 0)
+ {
+ path_contribution_msat = hop_used_msat;
+ } else { continue }
+ if let Some(first_channels) = first_hop_targets.get_mut(&NodeId::from_pubkey(&hint.1.introduction_node_id)) {
+ sort_first_hop_channels(first_channels, &used_liquidities, recommended_value_msat,
+ our_node_pubkey);
+ for details in first_channels {
+ let first_hop_candidate = CandidateRouteHop::FirstHop { details };
+ add_entry!(first_hop_candidate, our_node_id, intro_node_id, 0, path_contribution_msat, 0,
+ 0_u64, 0, 0);
+ }
+ }
+ }
+ for route in payment_params.payee.unblinded_route_hints().iter()
+ .filter(|route| !route.0.is_empty())
+ {
let first_hop_in_route = &(route.0)[0];
let have_hop_src_in_graph =
// Only add the hops in this route to our candidate set if either
hop_used = false;
}
- let used_liquidity_msat = used_channel_liquidities
- .get(&(hop.short_channel_id, source < target)).copied().unwrap_or(0);
+ let used_liquidity_msat = used_liquidities
+ .get(&candidate.id(source < target)).copied()
+ .unwrap_or(0);
let channel_usage = ChannelUsage {
amount_msat: final_value_msat + aggregate_next_hops_fee_msat,
inflight_htlc_msat: used_liquidity_msat,
// Searching for a direct channel between last checked hop and first_hop_targets
if let Some(first_channels) = first_hop_targets.get_mut(&NodeId::from_pubkey(&prev_hop_id)) {
- sort_first_hop_channels(first_channels, &used_channel_liquidities,
+ sort_first_hop_channels(first_channels, &used_liquidities,
recommended_value_msat, our_node_pubkey);
for details in first_channels {
let first_hop_candidate = CandidateRouteHop::FirstHop { details };
// always assumes that the third argument is a node to which we have a
// path.
if let Some(first_channels) = first_hop_targets.get_mut(&NodeId::from_pubkey(&hop.src_node_id)) {
- sort_first_hop_channels(first_channels, &used_channel_liquidities,
+ sort_first_hop_channels(first_channels, &used_liquidities,
recommended_value_msat, our_node_pubkey);
for details in first_channels {
let first_hop_candidate = CandidateRouteHop::FirstHop { details };
let mut features_set = false;
if let Some(first_channels) = first_hop_targets.get(&ordered_hops.last().unwrap().0.node_id) {
for details in first_channels {
- if details.get_outbound_payment_scid().unwrap() == ordered_hops.last().unwrap().0.candidate.short_channel_id() {
- ordered_hops.last_mut().unwrap().1 = details.counterparty.features.to_context();
- features_set = true;
- break;
+ if let Some(scid) = ordered_hops.last().unwrap().0.candidate.short_channel_id() {
+ if details.get_outbound_payment_scid().unwrap() == scid {
+ ordered_hops.last_mut().unwrap().1 = details.counterparty.features.to_context();
+ features_set = true;
+ break;
+ }
}
}
}
.chain(payment_path.hops.iter().map(|(hop, _)| &hop.node_id));
for (prev_hop, (hop, _)) in prev_hop_iter.zip(payment_path.hops.iter()) {
let spent_on_hop_msat = value_contribution_msat + hop.next_hops_fee_msat;
- let used_liquidity_msat = used_channel_liquidities
- .entry((hop.candidate.short_channel_id(), *prev_hop < hop.node_id))
+ let used_liquidity_msat = used_liquidities
+ .entry(hop.candidate.id(*prev_hop < hop.node_id))
.and_modify(|used_liquidity_msat| *used_liquidity_msat += spent_on_hop_msat)
.or_insert(spent_on_hop_msat);
let hop_capacity = hop.candidate.effective_capacity();
// If we weren't capped by hitting a liquidity limit on a channel in the path,
// we'll probably end up picking the same path again on the next iteration.
// Decrease the available liquidity of a hop in the middle of the path.
- let victim_scid = payment_path.hops[(payment_path.hops.len()) / 2].0.candidate.short_channel_id();
+ let victim_candidate = &payment_path.hops[(payment_path.hops.len()) / 2].0.candidate;
let exhausted = u64::max_value();
- log_trace!(logger, "Disabling channel {} for future path building iterations to avoid duplicates.", victim_scid);
- *used_channel_liquidities.entry((victim_scid, false)).or_default() = exhausted;
- *used_channel_liquidities.entry((victim_scid, true)).or_default() = exhausted;
+ log_trace!(logger, "Disabling route candidate {} for future path building iterations to
+ avoid duplicates.", LoggedCandidateHop(victim_candidate));
+ *used_liquidities.entry(victim_candidate.id(false)).or_default() = exhausted;
+ *used_liquidities.entry(victim_candidate.id(true)).or_default() = exhausted;
}
// Track the total amount all our collected paths allow to send so that we know
// compare both SCIDs and NodeIds as individual nodes may use random aliases causing collisions
// across nodes.
selected_route.sort_unstable_by_key(|path| {
- let mut key = [0u64; MAX_PATH_LENGTH_ESTIMATE as usize];
+ let mut key = [CandidateHopId::Clear((42, true)) ; MAX_PATH_LENGTH_ESTIMATE as usize];
debug_assert!(path.hops.len() <= key.len());
- for (scid, key) in path.hops.iter().map(|h| h.0.candidate.short_channel_id()).zip(key.iter_mut()) {
+ for (scid, key) in path.hops.iter() .map(|h| h.0.candidate.id(true)).zip(key.iter_mut()) {
*key = scid;
}
key
});
for idx in 0..(selected_route.len() - 1) {
if idx + 1 >= selected_route.len() { break; }
- if iter_equal(selected_route[idx ].hops.iter().map(|h| (h.0.candidate.short_channel_id(), h.0.node_id)),
- selected_route[idx + 1].hops.iter().map(|h| (h.0.candidate.short_channel_id(), h.0.node_id))) {
+ if iter_equal(selected_route[idx ].hops.iter().map(|h| (h.0.candidate.id(true), h.0.node_id)),
+ selected_route[idx + 1].hops.iter().map(|h| (h.0.candidate.id(true), h.0.node_id))) {
let new_value = selected_route[idx].get_value_msat() + selected_route[idx + 1].get_value_msat();
selected_route[idx].update_value_and_recompute_fees(new_value);
selected_route.remove(idx + 1);
}
}
- let mut selected_paths = Vec::<Vec<Result<RouteHop, LightningError>>>::new();
+ let mut paths = Vec::new();
for payment_path in selected_route {
- let mut path = payment_path.hops.iter().map(|(payment_hop, node_features)| {
- Ok(RouteHop {
- pubkey: PublicKey::from_slice(payment_hop.node_id.as_slice()).map_err(|_| LightningError{err: format!("Public key {:?} is invalid", &payment_hop.node_id), action: ErrorAction::IgnoreAndLog(Level::Trace)})?,
+ let mut hops = Vec::with_capacity(payment_path.hops.len());
+ for (hop, node_features) in payment_path.hops.iter()
+ .filter(|(h, _)| h.candidate.short_channel_id().is_some())
+ {
+ hops.push(RouteHop {
+ pubkey: PublicKey::from_slice(hop.node_id.as_slice()).map_err(|_| LightningError{err: format!("Public key {:?} is invalid", &hop.node_id), action: ErrorAction::IgnoreAndLog(Level::Trace)})?,
node_features: node_features.clone(),
- short_channel_id: payment_hop.candidate.short_channel_id(),
- channel_features: payment_hop.candidate.features(),
- fee_msat: payment_hop.fee_msat,
- cltv_expiry_delta: payment_hop.candidate.cltv_expiry_delta(),
- })
- }).collect::<Vec<_>>();
+ short_channel_id: hop.candidate.short_channel_id().unwrap(),
+ channel_features: hop.candidate.features(),
+ fee_msat: hop.fee_msat,
+ cltv_expiry_delta: hop.candidate.cltv_expiry_delta(),
+ });
+ }
+ let mut final_cltv_delta = final_cltv_expiry_delta;
+ let blinded_tail = payment_path.hops.last().and_then(|(h, _)| {
+ if let Some(blinded_path) = h.candidate.blinded_path() {
+ final_cltv_delta = h.candidate.cltv_expiry_delta();
+ Some(BlindedTail {
+ hops: blinded_path.blinded_hops.clone(),
+ blinding_point: blinded_path.blinding_point,
+ excess_final_cltv_expiry_delta: 0,
+ final_value_msat: h.fee_msat,
+ })
+ } else { None }
+ });
// Propagate the cltv_expiry_delta one hop backwards since the delta from the current hop is
// applicable for the previous hop.
- path.iter_mut().rev().fold(final_cltv_expiry_delta, |prev_cltv_expiry_delta, hop| {
- core::mem::replace(&mut hop.as_mut().unwrap().cltv_expiry_delta, prev_cltv_expiry_delta)
+ hops.iter_mut().rev().fold(final_cltv_delta, |prev_cltv_expiry_delta, hop| {
+ core::mem::replace(&mut hop.cltv_expiry_delta, prev_cltv_expiry_delta)
});
- selected_paths.push(path);
+
+ paths.push(Path { hops, blinded_tail });
}
// Make sure we would never create a route with more paths than we allow.
- debug_assert!(selected_paths.len() <= payment_params.max_path_count.into());
+ debug_assert!(paths.len() <= payment_params.max_path_count.into());
if let Some(node_features) = payment_params.payee.node_features() {
- for path in selected_paths.iter_mut() {
- if let Ok(route_hop) = path.last_mut().unwrap() {
- route_hop.node_features = node_features.clone();
- }
+ for path in paths.iter_mut() {
+ path.hops.last_mut().unwrap().node_features = node_features.clone();
}
}
- let mut paths: Vec<Path> = Vec::new();
- for results_vec in selected_paths {
- let mut hops = Vec::with_capacity(results_vec.len());
- for res in results_vec { hops.push(res?); }
- paths.push(Path { hops, blinded_tail: None });
- }
- let route = Route {
- paths,
- payment_params: Some(payment_params.clone()),
- };
+ let route = Route { paths, payment_params: Some(payment_params.clone()) };
log_info!(logger, "Got route: {}", log_route!(route));
Ok(route)
}
use crate::routing::test_utils::{add_channel, add_or_update_node, build_graph, build_line_graph, id_to_feature_flags, get_nodes, update_channel};
use crate::chain::transaction::OutPoint;
use crate::sign::EntropySource;
- use crate::ln::features::{ChannelFeatures, InitFeatures, NodeFeatures};
+ use crate::ln::features::{BlindedHopFeatures, Bolt12InvoiceFeatures, ChannelFeatures, InitFeatures, NodeFeatures};
use crate::ln::msgs::{ErrorAction, LightningError, UnsignedChannelUpdate, MAX_VALUE_MSAT};
use crate::ln::channelmanager;
+ use crate::offers::invoice::BlindedPayInfo;
use crate::util::config::UserConfig;
use crate::util::test_utils as ln_test_utils;
use crate::util::chacha20::ChaCha20;
#[test]
fn simple_mpp_route_test() {
+ let (secp_ctx, _, _, _, _) = build_graph();
+ let (_, _, _, nodes) = get_nodes(&secp_ctx);
+ let config = UserConfig::default();
+ let clear_payment_params = PaymentParameters::from_node_id(nodes[2], 42)
+ .with_bolt11_features(channelmanager::provided_invoice_features(&config)).unwrap();
+ do_simple_mpp_route_test(clear_payment_params);
+
+ // MPP to a 1-hop blinded path for nodes[2]
+ let bolt12_features: Bolt12InvoiceFeatures = channelmanager::provided_invoice_features(&config).to_context();
+ let blinded_path = BlindedPath {
+ introduction_node_id: nodes[2],
+ blinding_point: ln_test_utils::pubkey(42),
+ blinded_hops: vec![BlindedHop { blinded_node_id: ln_test_utils::pubkey(42 as u8), encrypted_payload: Vec::new() }],
+ };
+ let blinded_payinfo = BlindedPayInfo { // These fields are ignored for 1-hop blinded paths
+ fee_base_msat: 0,
+ fee_proportional_millionths: 0,
+ htlc_minimum_msat: 0,
+ htlc_maximum_msat: 0,
+ cltv_expiry_delta: 0,
+ features: BlindedHopFeatures::empty(),
+ };
+ let one_hop_blinded_payment_params = PaymentParameters::blinded(vec![(blinded_payinfo.clone(), blinded_path.clone())])
+ .with_bolt12_features(bolt12_features.clone()).unwrap();
+ do_simple_mpp_route_test(one_hop_blinded_payment_params.clone());
+
+ // MPP to 3 2-hop blinded paths
+ let mut blinded_path_node_0 = blinded_path.clone();
+ blinded_path_node_0.introduction_node_id = nodes[0];
+ blinded_path_node_0.blinded_hops.push(blinded_path.blinded_hops[0].clone());
+ let mut node_0_payinfo = blinded_payinfo.clone();
+ node_0_payinfo.htlc_maximum_msat = 50_000;
+
+ let mut blinded_path_node_7 = blinded_path_node_0.clone();
+ blinded_path_node_7.introduction_node_id = nodes[7];
+ let mut node_7_payinfo = blinded_payinfo.clone();
+ node_7_payinfo.htlc_maximum_msat = 60_000;
+
+ let mut blinded_path_node_1 = blinded_path_node_0.clone();
+ blinded_path_node_1.introduction_node_id = nodes[1];
+ let mut node_1_payinfo = blinded_payinfo.clone();
+ node_1_payinfo.htlc_maximum_msat = 180_000;
+
+ let two_hop_blinded_payment_params = PaymentParameters::blinded(
+ vec![
+ (node_0_payinfo, blinded_path_node_0),
+ (node_7_payinfo, blinded_path_node_7),
+ (node_1_payinfo, blinded_path_node_1)
+ ])
+ .with_bolt12_features(bolt12_features).unwrap();
+ do_simple_mpp_route_test(two_hop_blinded_payment_params);
+ }
+
+
+ fn do_simple_mpp_route_test(payment_params: PaymentParameters) {
let (secp_ctx, network_graph, gossip_sync, _, logger) = build_graph();
let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
let scorer = ln_test_utils::TestScorer::new();
let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
let random_seed_bytes = keys_manager.get_secure_random_bytes();
- let config = UserConfig::default();
- let payment_params = PaymentParameters::from_node_id(nodes[2], 42)
- .with_bolt11_features(channelmanager::provided_invoice_features(&config)).unwrap();
// We need a route consisting of 3 paths:
// From our node to node2 via node0, node7, node1 (three paths one hop each).
assert_eq!(route.paths.len(), 3);
let mut total_amount_paid_msat = 0;
for path in &route.paths {
- assert_eq!(path.hops.len(), 2);
- assert_eq!(path.hops.last().unwrap().pubkey, nodes[2]);
+ if let Some(bt) = &path.blinded_tail {
+ assert_eq!(path.hops.len() + if bt.hops.len() == 1 { 0 } else { 1 }, 2);
+ } else {
+ assert_eq!(path.hops.len(), 2);
+ assert_eq!(path.hops.last().unwrap().pubkey, nodes[2]);
+ }
total_amount_paid_msat += path.final_value_msat();
}
assert_eq!(total_amount_paid_msat, 250_000);
assert_eq!(route.paths.len(), 3);
let mut total_amount_paid_msat = 0;
for path in &route.paths {
- assert_eq!(path.hops.len(), 2);
- assert_eq!(path.hops.last().unwrap().pubkey, nodes[2]);
+ if payment_params.payee.blinded_route_hints().len() != 0 {
+ assert!(path.blinded_tail.is_some()) } else { assert!(path.blinded_tail.is_none()) }
+ if let Some(bt) = &path.blinded_tail {
+ assert_eq!(path.hops.len() + if bt.hops.len() == 1 { 0 } else { 1 }, 2);
+ if bt.hops.len() > 1 {
+ assert_eq!(path.hops.last().unwrap().pubkey,
+ payment_params.payee.blinded_route_hints().iter()
+ .find(|(p, _)| p.htlc_maximum_msat == path.final_value_msat())
+ .map(|(_, p)| p.introduction_node_id).unwrap());
+ } else {
+ assert_eq!(path.hops.last().unwrap().pubkey, nodes[2]);
+ }
+ } else {
+ assert_eq!(path.hops.len(), 2);
+ assert_eq!(path.hops.last().unwrap().pubkey, nodes[2]);
+ }
total_amount_paid_msat += path.final_value_msat();
}
assert_eq!(total_amount_paid_msat, 290_000);
assert!(route.paths[0].hops.last().unwrap().fee_msat <= max_htlc_msat);
assert!(route.paths[1].hops.last().unwrap().fee_msat <= max_htlc_msat);
assert_eq!(route.get_total_amount(), amt_msat);
+
+ // Make sure this works for blinded route hints.
+ let blinded_path = BlindedPath {
+ introduction_node_id: intermed_node_id,
+ blinding_point: ln_test_utils::pubkey(42),
+ blinded_hops: vec![
+ BlindedHop { blinded_node_id: ln_test_utils::pubkey(42), encrypted_payload: vec![] },
+ BlindedHop { blinded_node_id: ln_test_utils::pubkey(43), encrypted_payload: vec![] },
+ ],
+ };
+ let blinded_payinfo = BlindedPayInfo {
+ fee_base_msat: 100,
+ fee_proportional_millionths: 0,
+ htlc_minimum_msat: 1,
+ htlc_maximum_msat: max_htlc_msat,
+ cltv_expiry_delta: 10,
+ features: BlindedHopFeatures::empty(),
+ };
+ let bolt12_features: Bolt12InvoiceFeatures = channelmanager::provided_invoice_features(&config).to_context();
+ let payment_params = PaymentParameters::blinded(vec![
+ (blinded_payinfo.clone(), blinded_path.clone()),
+ (blinded_payinfo.clone(), blinded_path.clone())])
+ .with_bolt12_features(bolt12_features).unwrap();
+ let route = get_route(&our_node_id, &payment_params, &network_graph.read_only(),
+ Some(&first_hops.iter().collect::<Vec<_>>()), amt_msat, Arc::clone(&logger), &scorer, &(),
+ &random_seed_bytes).unwrap();
+ assert_eq!(route.paths.len(), 2);
+ assert!(route.paths[0].hops.last().unwrap().fee_msat <= max_htlc_msat);
+ assert!(route.paths[1].hops.last().unwrap().fee_msat <= max_htlc_msat);
+ assert_eq!(route.get_total_amount(), amt_msat);
}
#[test]
assert_eq!(route.paths[0].blinded_tail.as_ref().unwrap().excess_final_cltv_expiry_delta, 40);
assert_eq!(route.paths[0].hops.last().unwrap().cltv_expiry_delta, 40);
}
+
+ #[test]
+ fn simple_blinded_route_hints() {
+ do_simple_blinded_route_hints(1);
+ do_simple_blinded_route_hints(2);
+ do_simple_blinded_route_hints(3);
+ }
+
+ fn do_simple_blinded_route_hints(num_blinded_hops: usize) {
+ // Check that we can generate a route to a blinded path with the expected hops.
+ let (secp_ctx, network, _, _, logger) = build_graph();
+ let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
+ let network_graph = network.read_only();
+
+ let scorer = ln_test_utils::TestScorer::new();
+ let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
+ let random_seed_bytes = keys_manager.get_secure_random_bytes();
+
+ let mut blinded_path = BlindedPath {
+ introduction_node_id: nodes[2],
+ blinding_point: ln_test_utils::pubkey(42),
+ blinded_hops: Vec::with_capacity(num_blinded_hops),
+ };
+ for i in 0..num_blinded_hops {
+ blinded_path.blinded_hops.push(
+ BlindedHop { blinded_node_id: ln_test_utils::pubkey(42 + i as u8), encrypted_payload: Vec::new() },
+ );
+ }
+ let blinded_payinfo = BlindedPayInfo {
+ fee_base_msat: 100,
+ fee_proportional_millionths: 500,
+ htlc_minimum_msat: 1000,
+ htlc_maximum_msat: 100_000_000,
+ cltv_expiry_delta: 15,
+ features: BlindedHopFeatures::empty(),
+ };
+
+ let final_amt_msat = 1001;
+ let payment_params = PaymentParameters::blinded(vec![(blinded_payinfo.clone(), blinded_path.clone())]);
+ let route = get_route(&our_id, &payment_params, &network_graph, None, final_amt_msat , Arc::clone(&logger),
+ &scorer, &(), &random_seed_bytes).unwrap();
+ assert_eq!(route.paths.len(), 1);
+ assert_eq!(route.paths[0].hops.len(), 2);
+
+ let tail = route.paths[0].blinded_tail.as_ref().unwrap();
+ assert_eq!(tail.hops, blinded_path.blinded_hops);
+ assert_eq!(tail.excess_final_cltv_expiry_delta, 0);
+ assert_eq!(tail.final_value_msat, 1001);
+
+ let final_hop = route.paths[0].hops.last().unwrap();
+ assert_eq!(final_hop.pubkey, blinded_path.introduction_node_id);
+ if tail.hops.len() > 1 {
+ assert_eq!(final_hop.fee_msat,
+ blinded_payinfo.fee_base_msat as u64 + blinded_payinfo.fee_proportional_millionths as u64 * tail.final_value_msat / 1000000);
+ assert_eq!(final_hop.cltv_expiry_delta, blinded_payinfo.cltv_expiry_delta as u32);
+ } else {
+ assert_eq!(final_hop.fee_msat, 0);
+ assert_eq!(final_hop.cltv_expiry_delta, 0);
+ }
+ }
+
+ #[test]
+ fn blinded_path_routing_errors() {
+ // Check that we can generate a route to a blinded path with the expected hops.
+ let (secp_ctx, network, _, _, logger) = build_graph();
+ let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
+ let network_graph = network.read_only();
+
+ let scorer = ln_test_utils::TestScorer::new();
+ let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
+ let random_seed_bytes = keys_manager.get_secure_random_bytes();
+
+ let mut invalid_blinded_path = BlindedPath {
+ introduction_node_id: nodes[2],
+ blinding_point: ln_test_utils::pubkey(42),
+ blinded_hops: vec![
+ BlindedHop { blinded_node_id: ln_test_utils::pubkey(43), encrypted_payload: vec![0; 43] },
+ ],
+ };
+ let blinded_payinfo = BlindedPayInfo {
+ fee_base_msat: 100,
+ fee_proportional_millionths: 500,
+ htlc_minimum_msat: 1000,
+ htlc_maximum_msat: 100_000_000,
+ cltv_expiry_delta: 15,
+ features: BlindedHopFeatures::empty(),
+ };
+
+ let mut invalid_blinded_path_2 = invalid_blinded_path.clone();
+ invalid_blinded_path_2.introduction_node_id = ln_test_utils::pubkey(45);
+ let payment_params = PaymentParameters::blinded(vec![
+ (blinded_payinfo.clone(), invalid_blinded_path.clone()),
+ (blinded_payinfo.clone(), invalid_blinded_path_2)]);
+ match get_route(&our_id, &payment_params, &network_graph, None, 1001, Arc::clone(&logger),
+ &scorer, &(), &random_seed_bytes)
+ {
+ Err(LightningError { err, .. }) => {
+ assert_eq!(err, "1-hop blinded paths must all have matching introduction node ids");
+ },
+ _ => panic!("Expected error")
+ }
+
+ invalid_blinded_path.introduction_node_id = our_id;
+ let payment_params = PaymentParameters::blinded(vec![(blinded_payinfo.clone(), invalid_blinded_path.clone())]);
+ match get_route(&our_id, &payment_params, &network_graph, None, 1001, Arc::clone(&logger),
+ &scorer, &(), &random_seed_bytes)
+ {
+ Err(LightningError { err, .. }) => {
+ assert_eq!(err, "Cannot generate a route to blinded paths if we are the introduction node to all of them");
+ },
+ _ => panic!("Expected error")
+ }
+
+ invalid_blinded_path.introduction_node_id = ln_test_utils::pubkey(46);
+ invalid_blinded_path.blinded_hops.clear();
+ let payment_params = PaymentParameters::blinded(vec![(blinded_payinfo, invalid_blinded_path)]);
+ match get_route(&our_id, &payment_params, &network_graph, None, 1001, Arc::clone(&logger),
+ &scorer, &(), &random_seed_bytes)
+ {
+ Err(LightningError { err, .. }) => {
+ assert_eq!(err, "0-hop blinded path provided");
+ },
+ _ => panic!("Expected error")
+ }
+ }
+
+ #[test]
+ fn matching_intro_node_paths_provided() {
+ // Check that if multiple blinded paths with the same intro node are provided in payment
+ // parameters, we'll return the correct paths in the resulting MPP route.
+ let (secp_ctx, network, _, _, logger) = build_graph();
+ let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
+ let network_graph = network.read_only();
+
+ let scorer = ln_test_utils::TestScorer::new();
+ let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
+ let random_seed_bytes = keys_manager.get_secure_random_bytes();
+ let config = UserConfig::default();
+
+ let bolt12_features: Bolt12InvoiceFeatures = channelmanager::provided_invoice_features(&config).to_context();
+ let blinded_path_1 = BlindedPath {
+ introduction_node_id: nodes[2],
+ blinding_point: ln_test_utils::pubkey(42),
+ blinded_hops: vec![
+ BlindedHop { blinded_node_id: ln_test_utils::pubkey(42 as u8), encrypted_payload: Vec::new() },
+ BlindedHop { blinded_node_id: ln_test_utils::pubkey(42 as u8), encrypted_payload: Vec::new() }
+ ],
+ };
+ let blinded_payinfo_1 = BlindedPayInfo {
+ fee_base_msat: 0,
+ fee_proportional_millionths: 0,
+ htlc_minimum_msat: 0,
+ htlc_maximum_msat: 30_000,
+ cltv_expiry_delta: 0,
+ features: BlindedHopFeatures::empty(),
+ };
+
+ let mut blinded_path_2 = blinded_path_1.clone();
+ blinded_path_2.blinding_point = ln_test_utils::pubkey(43);
+ let mut blinded_payinfo_2 = blinded_payinfo_1.clone();
+ blinded_payinfo_2.htlc_maximum_msat = 70_000;
+
+ let blinded_hints = vec![
+ (blinded_payinfo_1.clone(), blinded_path_1.clone()),
+ (blinded_payinfo_2.clone(), blinded_path_2.clone()),
+ ];
+ let payment_params = PaymentParameters::blinded(blinded_hints.clone())
+ .with_bolt12_features(bolt12_features.clone()).unwrap();
+
+ let route = get_route(&our_id, &payment_params, &network_graph, None,
+ 100_000, Arc::clone(&logger), &scorer, &(), &random_seed_bytes).unwrap();
+ assert_eq!(route.paths.len(), 2);
+ let mut total_amount_paid_msat = 0;
+ for path in route.paths.into_iter() {
+ assert_eq!(path.hops.last().unwrap().pubkey, nodes[2]);
+ if let Some(bt) = &path.blinded_tail {
+ assert_eq!(bt.blinding_point,
+ blinded_hints.iter().find(|(p, _)| p.htlc_maximum_msat == path.final_value_msat())
+ .map(|(_, bp)| bp.blinding_point).unwrap());
+ } else { panic!(); }
+ total_amount_paid_msat += path.final_value_msat();
+ }
+ assert_eq!(total_amount_paid_msat, 100_000);
+ }
}
#[cfg(all(any(test, ldk_bench), not(feature = "no-std")))]
projects / rust-lightning / blobdiff