core-lightning/lightningd/notification.h
trueptolemy e75d8e061b Plugin: New notification type, forward_event
`forward_event`

A notification for topic `forward_event` is sent every time the status
of a forward payment is set. The json format is same as the API
`listforwards`.

```json
{
  "forward_event": {
  "payment_hash": "f5a6a059a25d1e329d9b094aeeec8c2191ca037d3f5b0662e21ae850debe8ea2",
  "in_channel": "103x2x1",
  "out_channel": "103x1x1",
  "in_msatoshi": 100001001,
  "in_msat": "100001001msat",
  "out_msatoshi": 100000000,
  "out_msat": "100000000msat",
  "fee": 1001,
  "fee_msat": "1001msat",
  "status": "settled",
  "received_time": 1560696342.368,
  "resolved_time": 1560696342.556
  }
}
```
or

```json
{
  "forward_event": {
  "payment_hash": "ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff",
  "in_channel": "103x2x1",
  "out_channel": "110x1x0",
  "in_msatoshi": 100001001,
  "in_msat": "100001001msat",
  "out_msatoshi": 100000000,
  "out_msat": "100000000msat",
  "fee": 1001,
  "fee_msat": "1001msat",
  "status": "local_failed",
  "failcode": 16392,
  "failreason": "WIRE_PERMANENT_CHANNEL_FAILURE",
  "received_time": 1560696343.052
  }
}

```
 - The status includes `offered`, `settled`, `failed` and `local_failed`,
   and they are all string type in json.
   - When the forward payment is valid for us, we'll set `offered`
     and send the forward payment to next hop to resolve;
   - When the payment forwarded by us gets paid eventually, the forward
     payment will change the status from `offered` to `settled`;
   - If payment fails locally(like failing to resolve locally) or the
     corresponding htlc with next hop fails(like htlc timeout), we will
     set the status as `local_failed`. `local_failed` may be set before
     setting `offered` or after setting `offered`. In fact, from the
     time we receive the htlc of the previous hop, all we can know the
     cause of the failure is treated as `local_failed`. `local_failed`
     only occuors locally or happens in the htlc between us and next hop;
     - If `local_failed` is set before `offered`, this
       means we just received htlc from the previous hop and haven't
       generate htlc for next hop. In this case, the json of `forward_event`
       sets the fields of `out_msatoshi`, `out_msat`,`fee` and `out_channel`
       as 0;
       - Note: In fact, for this case we may be not sure if this incoming
         htlc represents a pay to us or a payment we need to forward.
         We just simply treat all incoming failed to resolve as
         `local_failed`.
     - Only in `local_failed` case, json includes `failcode` and
       `failreason` fields;
   - `failed` means the payment forwarded by us fails in the
     latter hops, and the failure isn't related to us, so we aren't
     accessed to the fail reason. `failed` must be set after
     `offered`.
     - `failed` case doesn't include `failcode` and `failreason`
       fields;
 - `received_time` means when we received the htlc of this payment from
   the previous peer. It will be contained into all status case;
 - `resolved_time` means when the htlc of this payment between us and the
   next peer was resolved. The resolved result may success or fail, so
   only `settled` and `failed` case contain `resolved_time`;
 - The `failcode` and `failreason` are defined in [BOLT 4][bolt4-failure-codes].
2019-08-01 18:49:25 +08:00

38 lines
1.3 KiB
C

#ifndef LIGHTNING_LIGHTNINGD_NOTIFICATION_H
#define LIGHTNING_LIGHTNINGD_NOTIFICATION_H
#include "config.h"
#include <bitcoin/short_channel_id.h>
#include <bitcoin/tx.h>
#include <ccan/json_escape/json_escape.h>
#include <common/amount.h>
#include <common/node_id.h>
#include <lightningd/jsonrpc.h>
#include <lightningd/lightningd.h>
#include <lightningd/log.h>
#include <lightningd/plugin.h>
#include <wallet/wallet.h>
bool notifications_have_topic(const char *topic);
void notify_connect(struct lightningd *ld, struct node_id *nodeid,
struct wireaddr_internal *addr);
void notify_disconnect(struct lightningd *ld, struct node_id *nodeid);
void notify_warning(struct lightningd *ld, struct log_entry *l);
void notify_invoice_payment(struct lightningd *ld, struct amount_msat amount,
struct preimage preimage, const struct json_escape *label);
void notify_channel_opened(struct lightningd *ld, struct node_id *node_id,
struct amount_sat *funding_sat, struct bitcoin_txid *funding_txid,
bool *funding_locked);
void notify_forward_event(struct lightningd *ld,
const struct htlc_in *in,
const struct htlc_out *out,
enum forward_status state,
enum onion_type failcode,
struct timeabs *resolved_time);
#endif /* LIGHTNING_LIGHTNINGD_NOTIFICATION_H */