1 //! Logic to connect off-chain channel management with on-chain transaction monitoring.
3 //! [`ChainMonitor`] is an implementation of [`chain::Watch`] used both to process blocks and to
4 //! update [`ChannelMonitor`]s accordingly. If any on-chain events need further processing, it will
5 //! make those available as [`MonitorEvent`]s to be consumed.
7 //! `ChainMonitor` is parameterized by an optional chain source, which must implement the
8 //! [`chain::Filter`] trait. This provides a mechanism to signal new relevant outputs back to light
9 //! clients, such that transactions spending those outputs are included in block data.
11 //! `ChainMonitor` may be used directly to monitor channels locally or as a part of a distributed
12 //! setup to monitor channels remotely. In the latter case, a custom `chain::Watch` implementation
13 //! would be responsible for routing each update to a remote server and for retrieving monitor
14 //! events. The remote server would make use of `ChainMonitor` for block processing and for
15 //! servicing `ChannelMonitor` updates from the client.
17 //! [`ChainMonitor`]: struct.ChainMonitor.html
18 //! [`chain::Filter`]: ../trait.Filter.html
19 //! [`chain::Watch`]: ../trait.Watch.html
20 //! [`ChannelMonitor`]: ../channelmonitor/struct.ChannelMonitor.html
21 //! [`MonitorEvent`]: ../channelmonitor/enum.MonitorEvent.html
24 use bitcoin::hashes::Hash;
25 use crate::c_types::*;
28 use lightning::chain::chainmonitor::ChainMonitor as nativeChainMonitorImport;
29 type nativeChainMonitor = nativeChainMonitorImport<crate::chain::keysinterface::Sign, crate::chain::Filter, crate::chain::chaininterface::BroadcasterInterface, crate::chain::chaininterface::FeeEstimator, crate::util::logger::Logger, crate::chain::channelmonitor::Persist>;
31 /// An implementation of [`chain::Watch`] for monitoring channels.
33 /// Connected and disconnected blocks must be provided to `ChainMonitor` as documented by
34 /// [`chain::Watch`]. May be used in conjunction with [`ChannelManager`] to monitor channels locally
35 /// or used independently to monitor channels remotely. See the [module-level documentation] for
38 /// [`chain::Watch`]: ../trait.Watch.html
39 /// [`ChannelManager`]: ../../ln/channelmanager/struct.ChannelManager.html
40 /// [module-level documentation]: index.html
43 pub struct ChainMonitor {
44 /// A pointer to the opaque Rust object.
46 /// Nearly everywhere, inner must be non-null, however in places where
47 /// the Rust equivalent takes an Option, it may be set to null to indicate None.
48 pub inner: *mut nativeChainMonitor,
49 /// Indicates that this is the only struct which contains the same pointer.
51 /// Rust functions which take ownership of an object provided via an argument require
52 /// this to be true and invalidate the object pointed to by inner.
56 impl Drop for ChainMonitor {
58 if self.is_owned && !<*mut nativeChainMonitor>::is_null(self.inner) {
59 let _ = unsafe { Box::from_raw(self.inner) };
63 /// Frees any resources used by the ChainMonitor, if is_owned is set and inner is non-NULL.
65 pub extern "C" fn ChainMonitor_free(this_obj: ChainMonitor) { }
67 /// Used only if an object of this type is returned as a trait impl by a method
68 extern "C" fn ChainMonitor_free_void(this_ptr: *mut c_void) {
69 unsafe { let _ = Box::from_raw(this_ptr as *mut nativeChainMonitor); }
72 /// When moving out of the pointer, we have to ensure we aren't a reference, this makes that easy
74 pub(crate) fn take_inner(mut self) -> *mut nativeChainMonitor {
75 assert!(self.is_owned);
77 self.inner = std::ptr::null_mut();
81 /// Dispatches to per-channel monitors, which are responsible for updating their on-chain view
82 /// of a channel and reacting accordingly based on transactions in the connected block. See
83 /// [`ChannelMonitor::block_connected`] for details. Any HTLCs that were resolved on chain will
84 /// be returned by [`chain::Watch::release_pending_monitor_events`].
86 /// Calls back to [`chain::Filter`] if any monitor indicated new outputs to watch. Subsequent
87 /// calls must not exclude any transactions matching the new outputs nor any in-block
88 /// descendants of such transactions. It is not necessary to re-fetch the block to obtain
91 /// [`ChannelMonitor::block_connected`]: ../channelmonitor/struct.ChannelMonitor.html#method.block_connected
92 /// [`chain::Watch::release_pending_monitor_events`]: ../trait.Watch.html#tymethod.release_pending_monitor_events
93 /// [`chain::Filter`]: ../trait.Filter.html
95 pub extern "C" fn ChainMonitor_block_connected(this_arg: &ChainMonitor, header: *const [u8; 80], mut txdata: crate::c_types::derived::CVec_C2Tuple_usizeTransactionZZ, mut height: u32) {
96 let mut local_txdata = Vec::new(); for mut item in txdata.into_rust().drain(..) { local_txdata.push( { let (mut orig_txdata_0_0, mut orig_txdata_0_1) = item.to_rust(); let mut local_txdata_0 = (orig_txdata_0_0, orig_txdata_0_1.into_bitcoin()); local_txdata_0 }); };
97 unsafe { &*this_arg.inner }.block_connected(&::bitcoin::consensus::encode::deserialize(unsafe { &*header }).unwrap(), &local_txdata.iter().map(|(a, b)| (*a, b)).collect::<Vec<_>>()[..], height)
100 /// Dispatches to per-channel monitors, which are responsible for updating their on-chain view
101 /// of a channel based on the disconnected block. See [`ChannelMonitor::block_disconnected`] for
104 /// [`ChannelMonitor::block_disconnected`]: ../channelmonitor/struct.ChannelMonitor.html#method.block_disconnected
106 pub extern "C" fn ChainMonitor_block_disconnected(this_arg: &ChainMonitor, header: *const [u8; 80], mut disconnected_height: u32) {
107 unsafe { &*this_arg.inner }.block_disconnected(&::bitcoin::consensus::encode::deserialize(unsafe { &*header }).unwrap(), disconnected_height)
110 /// Creates a new `ChainMonitor` used to watch on-chain activity pertaining to channels.
112 /// When an optional chain source implementing [`chain::Filter`] is provided, the chain monitor
113 /// will call back to it indicating transactions and outputs of interest. This allows clients to
114 /// pre-filter blocks or only fetch blocks matching a compact filter. Otherwise, clients may
115 /// always need to fetch full blocks absent another means for determining which blocks contain
116 /// transactions relevant to the watched channels.
118 /// [`chain::Filter`]: ../trait.Filter.html
121 pub extern "C" fn ChainMonitor_new(chain_source: *mut crate::chain::Filter, mut broadcaster: crate::chain::chaininterface::BroadcasterInterface, mut logger: crate::util::logger::Logger, mut feeest: crate::chain::chaininterface::FeeEstimator, mut persister: crate::chain::channelmonitor::Persist) -> ChainMonitor {
122 let mut local_chain_source = if chain_source == std::ptr::null_mut() { None } else { Some( { unsafe { *Box::from_raw(chain_source) } }) };
123 let mut ret = lightning::chain::chainmonitor::ChainMonitor::new(local_chain_source, broadcaster, logger, feeest, persister);
124 ChainMonitor { inner: Box::into_raw(Box::new(ret)), is_owned: true }
127 impl From<nativeChainMonitor> for crate::chain::Watch {
128 fn from(obj: nativeChainMonitor) -> Self {
129 let mut rust_obj = ChainMonitor { inner: Box::into_raw(Box::new(obj)), is_owned: true };
130 let mut ret = ChainMonitor_as_Watch(&rust_obj);
131 // We want to free rust_obj when ret gets drop()'d, not rust_obj, so wipe rust_obj's pointer and set ret's free() fn
132 rust_obj.inner = std::ptr::null_mut();
133 ret.free = Some(ChainMonitor_free_void);
137 /// Constructs a new Watch which calls the relevant methods on this_arg.
138 /// This copies the `inner` pointer in this_arg and thus the returned Watch must be freed before this_arg is
140 pub extern "C" fn ChainMonitor_as_Watch(this_arg: &ChainMonitor) -> crate::chain::Watch {
141 crate::chain::Watch {
142 this_arg: unsafe { (*this_arg).inner as *mut c_void },
144 watch_channel: ChainMonitor_Watch_watch_channel,
145 update_channel: ChainMonitor_Watch_update_channel,
146 release_pending_monitor_events: ChainMonitor_Watch_release_pending_monitor_events,
151 extern "C" fn ChainMonitor_Watch_watch_channel(this_arg: *const c_void, mut funding_outpoint: crate::chain::transaction::OutPoint, mut monitor: crate::chain::channelmonitor::ChannelMonitor) -> crate::c_types::derived::CResult_NoneChannelMonitorUpdateErrZ {
152 let mut ret = <nativeChainMonitor as lightning::chain::Watch<_>>::watch_channel(unsafe { &mut *(this_arg as *mut nativeChainMonitor) }, *unsafe { Box::from_raw(funding_outpoint.take_inner()) }, *unsafe { Box::from_raw(monitor.take_inner()) });
153 let mut local_ret = match ret { Ok(mut o) => crate::c_types::CResultTempl::ok( { 0u8 /*o*/ }).into(), Err(mut e) => crate::c_types::CResultTempl::err( { crate::chain::channelmonitor::ChannelMonitorUpdateErr::native_into(e) }).into() };
157 extern "C" fn ChainMonitor_Watch_update_channel(this_arg: *const c_void, mut funding_txo: crate::chain::transaction::OutPoint, mut update: crate::chain::channelmonitor::ChannelMonitorUpdate) -> crate::c_types::derived::CResult_NoneChannelMonitorUpdateErrZ {
158 let mut ret = <nativeChainMonitor as lightning::chain::Watch<_>>::update_channel(unsafe { &mut *(this_arg as *mut nativeChainMonitor) }, *unsafe { Box::from_raw(funding_txo.take_inner()) }, *unsafe { Box::from_raw(update.take_inner()) });
159 let mut local_ret = match ret { Ok(mut o) => crate::c_types::CResultTempl::ok( { 0u8 /*o*/ }).into(), Err(mut e) => crate::c_types::CResultTempl::err( { crate::chain::channelmonitor::ChannelMonitorUpdateErr::native_into(e) }).into() };
163 extern "C" fn ChainMonitor_Watch_release_pending_monitor_events(this_arg: *const c_void) -> crate::c_types::derived::CVec_MonitorEventZ {
164 let mut ret = <nativeChainMonitor as lightning::chain::Watch<_>>::release_pending_monitor_events(unsafe { &mut *(this_arg as *mut nativeChainMonitor) }, );
165 let mut local_ret = Vec::new(); for mut item in ret.drain(..) { local_ret.push( { crate::chain::channelmonitor::MonitorEvent::native_into(item) }); };
169 impl From<nativeChainMonitor> for crate::util::events::EventsProvider {
170 fn from(obj: nativeChainMonitor) -> Self {
171 let mut rust_obj = ChainMonitor { inner: Box::into_raw(Box::new(obj)), is_owned: true };
172 let mut ret = ChainMonitor_as_EventsProvider(&rust_obj);
173 // We want to free rust_obj when ret gets drop()'d, not rust_obj, so wipe rust_obj's pointer and set ret's free() fn
174 rust_obj.inner = std::ptr::null_mut();
175 ret.free = Some(ChainMonitor_free_void);
179 /// Constructs a new EventsProvider which calls the relevant methods on this_arg.
180 /// This copies the `inner` pointer in this_arg and thus the returned EventsProvider must be freed before this_arg is
182 pub extern "C" fn ChainMonitor_as_EventsProvider(this_arg: &ChainMonitor) -> crate::util::events::EventsProvider {
183 crate::util::events::EventsProvider {
184 this_arg: unsafe { (*this_arg).inner as *mut c_void },
186 get_and_clear_pending_events: ChainMonitor_EventsProvider_get_and_clear_pending_events,
191 extern "C" fn ChainMonitor_EventsProvider_get_and_clear_pending_events(this_arg: *const c_void) -> crate::c_types::derived::CVec_EventZ {
192 let mut ret = <nativeChainMonitor as lightning::util::events::EventsProvider<>>::get_and_clear_pending_events(unsafe { &mut *(this_arg as *mut nativeChainMonitor) }, );
193 let mut local_ret = Vec::new(); for mut item in ret.drain(..) { local_ret.push( { crate::util::events::Event::native_into(item) }); };