impl Node {
pub(in crate::node) async fn handle_session_payload(
&mut self,
delivery: LocalSessionPayload<'_>,
) {
let src_addr = *delivery.source_addr();
let payload = delivery.payload();
let prefix = match FspCommonPrefix::parse(payload) {
Some(p) => p,
None => {
debug!(
len = payload.len(),
"Session payload too short for FSP prefix"
);
return;
}
};
let inner = &payload[FSP_COMMON_PREFIX_SIZE..];
match prefix.phase {
FSP_PHASE_MSG1 => {
self.handle_session_setup(&src_addr, inner).await;
}
FSP_PHASE_MSG2 => {
self.handle_session_ack(&src_addr, inner).await;
}
FSP_PHASE_MSG3 => {
self.handle_session_msg3(&src_addr, inner).await;
}
FSP_PHASE_ESTABLISHED if prefix.is_unencrypted() => {
if inner.is_empty() {
debug!("Empty plaintext error signal");
return;
}
let error_type = inner[0];
let error_body = &inner[1..];
match SessionMessageType::from_byte(error_type) {
Some(SessionMessageType::CoordsRequired) => {
self.handle_coords_required(error_body).await;
}
Some(SessionMessageType::PathBroken) => {
self.handle_path_broken(error_body).await;
}
Some(SessionMessageType::MtuExceeded) => {
self.handle_mtu_exceeded(error_body).await;
}
_ => {
debug!(error_type, "Unknown plaintext error signal type");
}
}
}
FSP_PHASE_ESTABLISHED => {
self.handle_encrypted_session_msg(delivery.into_encrypted())
.await;
}
_ => {
debug!(phase = prefix.phase, "Unknown FSP phase");
}
}
}
async fn handle_encrypted_session_msg(&mut self, delivery: EncryptedSessionPayload<'_>) {
let _t_fsp_handle =
crate::perf_profile::Timer::start(crate::perf_profile::Stage::FspHandle);
let src_addr = delivery.source_addr();
let payload = delivery.payload();
let mut wire = match EstablishedFspWire::parse(payload, *src_addr, *self.node_addr()) {
Ok(wire) => wire,
Err(EstablishedFspWireError::BadHeader) => {
debug!(
len = payload.len(),
"Encrypted session message too short for FSP header"
);
return;
}
Err(EstablishedFspWireError::BadCoords(e)) => {
debug!(error = %e, "Failed to parse coords from encrypted session message");
return;
}
};
if wire.has_coord_warmup() {
wire.apply_coord_warmup(&mut self.coord_cache, Self::now_ms());
}
let outcome = self.sessions.open_established_fsp_frame(
src_addr,
wire.receive(delivery.path_mtu(), delivery.ce_flag(), Self::now_ms()),
);
let session_message = match outcome {
FspFrameOutcome::Authentic(session_message) => session_message,
FspFrameOutcome::UnknownSession => {
debug!(src = %self.peer_display_name(src_addr), "Encrypted session message for unknown session");
return;
}
FspFrameOutcome::NotEstablished => {
debug!(
src = %self.peer_display_name(src_addr),
"Encrypted message but session not established (awaiting handshake completion)"
);
self.resend_handshake_after_early_encrypted_data(src_addr)
.await;
return;
}
FspFrameOutcome::BadInnerHeader => {
debug!(src = %self.peer_display_name(src_addr), "Decrypted payload too short for FSP inner header");
return;
}
FspFrameOutcome::MissingRemoteIdentity => {
debug!(
src = %self.peer_display_name(src_addr),
"Established session missing authenticated remote identity"
);
return;
}
FspFrameOutcome::DecryptFailed {
error,
counter,
consecutive,
recover_session,
} => {
debug!(
error = %error, src = %self.peer_display_name(src_addr),
counter, consecutive_failures = consecutive,
"Session AEAD decryption failed"
);
if recover_session {
warn!(
peer = %self.peer_display_name(src_addr),
consecutive_failures = consecutive,
"Session AEAD failures exceeded threshold; starting recovery rekey"
);
if !self.initiate_session_rekey(src_addr).await {
debug!(
peer = %self.peer_display_name(src_addr),
"Failed to start recovery rekey after decrypt-failure threshold"
);
}
}
return;
}
FspFrameOutcome::StaleEpochDrainFailure { counter } => {
trace!(
src = %self.peer_display_name(src_addr),
counter,
"Ignoring stale FSP packet from previous key epoch during drain"
);
return;
}
};
self.register_decrypt_worker_fsp_session(src_addr);
let dispatch = AuthenticatedSessionDispatch::new(
*src_addr,
*delivery.previous_hop_addr(),
delivery.ce_flag(),
session_message,
);
if dispatch.is_endpoint_data() {
let finish = dispatch.dispatch_endpoint_data_fast(self);
if let Some(dest_addr) = finish.pending_flush_dest() {
self.flush_pending_packets(&dest_addr).await;
}
return;
}
dispatch.dispatch(self).await;
}
fn record_worker_authenticated_fmp_receive(
&mut self,
fmp: &crate::node::decrypt_worker::DecryptFmpBookkeeping,
) {
let now = Instant::now();
let path_bookkeeping_allowed = self.authenticated_packet_path_allows_bookkeeping(
fmp.source_peer.node_addr(),
fmp.transport_id,
&fmp.remote_addr,
fmp.packet_timestamp_ms,
);
let bookkeeping = self.peers.record_authenticated_fmp_receive(
fmp.source_peer.node_addr(),
fmp.transport_id,
&fmp.remote_addr,
fmp.packet_timestamp_ms,
fmp.packet_len,
fmp.fmp_counter,
fmp.inner_timestamp_ms,
fmp.fmp_flags & FLAG_CE != 0,
fmp.fmp_flags & FLAG_SP != 0,
now,
path_bookkeeping_allowed,
);
#[cfg(any(target_os = "linux", target_os = "macos"))]
if bookkeeping.is_some_and(|update| update.address_changed) {
self.clear_connected_udp_for_peer(fmp.source_peer.node_addr());
}
#[cfg(not(any(target_os = "linux", target_os = "macos")))]
let _ = bookkeeping;
}
pub(in crate::node) fn process_authenticated_fmp_receive_from_worker(
&mut self,
receive: DecryptAuthenticatedFmpReceive,
) {
self.record_worker_authenticated_fmp_receive(&receive.fmp);
}
pub(in crate::node) async fn process_authenticated_session_from_worker(
&mut self,
authenticated: DecryptAuthenticatedSession,
) {
let now = Instant::now();
self.record_worker_authenticated_fmp_receive(&authenticated.fmp);
let source_addr = authenticated.source_addr;
let receive_applied = self.sessions.get_mut(&source_addr).is_some_and(|entry| {
entry.apply_fsp_receive_sync(authenticated.receive_sync, Self::now_ms(), now)
});
if !receive_applied {
debug!(
src = %self.peer_display_name(&source_addr),
"Dropping worker-authenticated session message for missing or stale session"
);
return;
}
let dispatch = AuthenticatedSessionDispatch::new(
source_addr,
*authenticated.previous_hop_peer.node_addr(),
authenticated.ce_flag,
authenticated.message,
);
if dispatch.is_endpoint_data() {
let finish = dispatch.dispatch_endpoint_data_fast(self);
if let Some(dest_addr) = finish.pending_flush_dest() {
self.flush_pending_packets(&dest_addr).await;
}
return;
}
dispatch.dispatch(self).await;
}
pub(in crate::node) async fn process_direct_session_data_from_worker(
&mut self,
direct: DecryptDirectSessionData,
) {
let Some(finish) = self.commit_direct_session_data_from_worker(
&direct.fmp,
direct.source_addr,
direct.previous_hop_peer,
direct.receive_sync,
direct.body_len,
) else {
return;
};
let source_addr = direct.source_addr;
match direct.delivery {
DecryptDirectSessionDelivery::Ipv6Packet(mut packet) => {
if direct.ce_flag {
mark_ipv6_ecn_ce(&mut packet);
self.stats_mut().congestion.record_ce_received();
}
if self.external_packet_tx.is_some() {
self.deliver_external_ipv6_packet(&source_addr, packet);
} else if let Some(tun_tx) = &self.tun_tx {
let _t =
crate::perf_profile::Timer::start(crate::perf_profile::Stage::TunWrite);
if let Err(error) = tun_tx.send(packet) {
debug!(error = %error, "Failed to deliver worker-decoded IPv6 packet to TUN");
}
} else {
trace!(
src = %self.peer_display_name(&source_addr),
"Worker-decoded IPv6 packet ready (no TUN interface)"
);
}
}
DecryptDirectSessionDelivery::EndpointData(delivery) => {
self.deliver_endpoint_data(delivery);
}
}
if let Some(dest_addr) = finish.pending_flush_dest() {
self.flush_pending_packets(&dest_addr).await;
}
}
pub(in crate::node) async fn process_direct_session_commit_from_worker(
&mut self,
commit: DecryptDirectSessionCommit,
) {
let Some(finish) = self.commit_direct_session_data_from_worker(
&commit.fmp,
commit.source_addr,
commit.previous_hop_peer,
commit.receive_sync,
commit.body_len,
) else {
return;
};
if commit.ce_flag && commit.delivered_ipv6 {
self.stats_mut().congestion.record_ce_received();
}
if let Some(dest_addr) = finish.pending_flush_dest() {
self.flush_pending_packets(&dest_addr).await;
}
}
fn commit_direct_session_data_from_worker(
&mut self,
fmp: &crate::node::decrypt_worker::DecryptFmpBookkeeping,
source_addr: NodeAddr,
previous_hop_peer: PeerIdentity,
receive_sync: crate::node::session::FspReceiveSync,
body_len: usize,
) -> Option<SessionDispatchFinish> {
let now = Instant::now();
self.record_worker_authenticated_fmp_receive(fmp);
let receive_applied = self
.sessions
.get_mut(&source_addr)
.is_some_and(|entry| entry.apply_fsp_receive_sync(receive_sync, Self::now_ms(), now));
if !receive_applied {
debug!(
src = %self.peer_display_name(&source_addr),
"Dropping worker-decoded direct session data for missing or stale session"
);
return None;
}
self.learn_reverse_route(source_addr, *previous_hop_peer.node_addr());
let finish = SessionDispatchCommit {
source_addr,
receive_completion: Some(SessionReceiveCompletion {
source_addr,
body_len,
}),
}
.finish_receive(self);
Some(finish)
}
pub(in crate::node) async fn process_fsp_decrypt_failure_from_worker(
&mut self,
report: DecryptFspFailureReport,
) {
self.record_worker_authenticated_fmp_receive(&report.fmp);
let src_addr = report.source_addr;
let Some(entry) = self.sessions.get_mut(&src_addr) else {
debug!(
src = %self.peer_display_name(&src_addr),
counter = report.counter,
"Worker FSP AEAD failure for unknown session"
);
return;
};
if should_ignore_stale_epoch_drain_failure(entry, report.received_k_bit) {
trace!(
src = %self.peer_display_name(&src_addr),
counter = report.counter,
"Ignoring worker FSP AEAD failure from stale previous key epoch during drain"
);
return;
}
let consecutive = entry.record_decrypt_failure();
let recover_session = should_start_decrypt_failure_rekey(entry, consecutive);
debug!(
src = %self.peer_display_name(&src_addr),
counter = report.counter,
consecutive_failures = consecutive,
"Worker FSP AEAD decryption failed"
);
if recover_session {
warn!(
peer = %self.peer_display_name(&src_addr),
consecutive_failures = consecutive,
"Session AEAD failures exceeded threshold; starting recovery rekey"
);
if !self.initiate_session_rekey(&src_addr).await {
debug!(
peer = %self.peer_display_name(&src_addr),
"Failed to start recovery rekey after worker FSP decrypt-failure threshold"
);
}
}
}
async fn handle_mesh_traversal_offer(&mut self, src_addr: &NodeAddr, body: &[u8]) {
let Some(bootstrap) = self.nostr_discovery.clone() else {
trace!(
src = %self.peer_display_name(src_addr),
"Ignoring mesh traversal offer without Nostr discovery runtime"
);
return;
};
if self.configured_peer(src_addr).is_none() {
debug!(
src = %self.peer_display_name(src_addr),
"Ignoring mesh traversal offer from unconfigured peer"
);
return;
}
let Some(sender_npub) = self.npub_for_node_addr(src_addr) else {
debug!(
src = %self.peer_display_name(src_addr),
"Ignoring mesh traversal offer without known sender npub"
);
return;
};
let offer = match serde_json::from_slice::<TraversalOffer>(body) {
Ok(offer) => offer,
Err(error) => {
debug!(
src = %self.peer_display_name(src_addr),
error = %error,
"Malformed mesh traversal offer"
);
return;
}
};
if offer.sender_npub != sender_npub {
debug!(
src = %self.peer_display_name(src_addr),
claimed = %offer.sender_npub,
actual = %sender_npub,
"Ignoring mesh traversal offer with sender mismatch"
);
return;
}
bootstrap
.receive_mesh_traversal_offer(offer, sender_npub)
.await;
}
async fn handle_mesh_traversal_answer(&mut self, src_addr: &NodeAddr, body: &[u8]) {
let Some(bootstrap) = self.nostr_discovery.clone() else {
trace!(
src = %self.peer_display_name(src_addr),
"Ignoring mesh traversal answer without Nostr discovery runtime"
);
return;
};
if self.configured_peer(src_addr).is_none() {
debug!(
src = %self.peer_display_name(src_addr),
"Ignoring mesh traversal answer from unconfigured peer"
);
return;
}
let Some(sender_npub) = self.npub_for_node_addr(src_addr) else {
debug!(
src = %self.peer_display_name(src_addr),
"Ignoring mesh traversal answer without known sender npub"
);
return;
};
let answer = match serde_json::from_slice::<TraversalAnswer>(body) {
Ok(answer) => answer,
Err(error) => {
debug!(
src = %self.peer_display_name(src_addr),
error = %error,
"Malformed mesh traversal answer"
);
return;
}
};
if answer.sender_npub != sender_npub {
debug!(
src = %self.peer_display_name(src_addr),
claimed = %answer.sender_npub,
actual = %sender_npub,
"Ignoring mesh traversal answer with sender mismatch"
);
return;
}
bootstrap
.receive_mesh_traversal_answer(answer, sender_npub)
.await;
}
}