json-rpc: Add `listforwardings` command

contrib/pylightning/lightning/lightning.py

@@ -428,6 +428,15 @@ class LightningRpc(UnixDomainSocketRpc):
         """
         return self.call("listfunds")
 
+    def getroutestats(self, details=True):
+        """Get statistics about routed payments.
+
+        If @details is True, this'll include the individual forwarded
+        payments.
+
+        """
+        return self.call("getroutestats", payload={'details': details})
+
     def dev_rescan_outputs(self):
         """
         Synchronize the state of our funds with bitcoind

lightningd/peer_htlcs.c

@@ -1842,3 +1842,82 @@ static const struct json_command dev_ignore_htlcs = {
 };
 AUTODATA(json_command, &dev_ignore_htlcs);
 #endif /* DEVELOPER */
+
+static void listforwardings_add_stats(struct json_result *response, struct wallet *wallet)
+{
+	const struct forwarding_stats *stats;
+	stats = wallet_forwarded_payments_stats(wallet, tmpctx);
+
+	json_object_start(response, "stats");
+	json_object_start(response, "settled");
+	json_add_num(response, "fee_msatoshis", stats->fee[FORWARD_SETTLED]);
+	json_add_num(response, "count", stats->count[FORWARD_SETTLED]);
+	json_add_num(response, "msatoshi", stats->msatoshi[FORWARD_SETTLED]);
+	json_object_end(response);
+
+	json_object_start(response, "failed");
+	json_add_num(response, "fee_msatoshis", stats->fee[FORWARD_FAILED]);
+	json_add_num(response, "count", stats->count[FORWARD_FAILED]);
+	json_add_num(response, "msatoshi", stats->msatoshi[FORWARD_FAILED]);
+	json_object_end(response);
+
+	json_object_start(response, "pending");
+	json_add_num(response, "fee_msatoshis", stats->fee[FORWARD_OFFERED]);
+	json_add_num(response, "count", stats->count[FORWARD_FAILED]);
+	json_add_num(response, "msatoshi", stats->msatoshi[FORWARD_FAILED]);
+	json_object_end(response);
+	json_object_end(response);
+
+	tal_free(stats);
+}
+
+static void listforwardings_add_forwardings(struct json_result *response, struct wallet *wallet)
+{
+	const struct forwarding *forwardings;
+	forwardings = wallet_forwarded_payments_get(wallet, tmpctx);
+
+	json_array_start(response, "forwards");
+	for (size_t i=0; i<tal_count(forwardings); i++) {
+		const struct forwarding *cur = &forwardings[i];
+		json_object_start(response, NULL);
+		json_add_short_channel_id(response, "in_channel", &cur->channel_in);
+		json_add_short_channel_id(response, "out_channel", &cur->channel_out);
+		json_add_num(response, "in_msatoshi", cur->msatoshi_in);
+		json_add_num(response, "out_msatoshi", cur->msatoshi_out);
+		json_add_num(response, "fee", cur->fee);
+		json_add_string(response, "status", forward_status_name(cur->status));
+		json_object_end(response);
+	}
+	json_array_end(response);
+
+	tal_free(forwardings);
+}
+
+static void json_getroutestats(struct command *cmd, const char *buffer,
+			       const jsmntok_t *params)
+{
+	struct json_result *response = new_json_result(cmd);
+	bool *details;
+
+	if (!param(cmd, buffer, params,
+		   p_opt_def("details", json_tok_bool, &details, true),
+		   NULL))
+		return;
+
+	json_object_start(response, NULL);
+	listforwardings_add_stats(response, cmd->ld->wallet);
+
+	if (*details)
+		listforwardings_add_forwardings(response, cmd->ld->wallet);
+
+	json_object_end(response);
+
+	command_success(cmd, response);
+}
+
+static const struct json_command getroutestats_command = {
+	"getroutestats", json_getroutestats,
+	"Get statistics about routed / forwarded payments", false,
+	"Get statistics about routed payments, i.e., the ones we aren't the initiator or recipient, including a detailed list if {details} is true."
+};
+AUTODATA(json_command, &getroutestats_command);

tests/test_pay.py

@@ -985,7 +985,7 @@ def test_forward_stats(node_factory, bitcoind):
     hash) and l5 will keep the HTLC dangling by disconnecting.
 
     """
-    amount = 10**4
+    amount = 10**5
     l1, l2, l3 = node_factory.line_graph(3, announce=False)
     l4 = node_factory.get_node()
     l5 = node_factory.get_node(may_fail=True)
@@ -1046,3 +1046,7 @@ def test_forward_stats(node_factory, bitcoind):
     assert outchan['out_msatoshi_offered'] == outchan['out_msatoshi_fulfilled']
 
     assert outchan['out_msatoshi_fulfilled'] < inchan['in_msatoshi_fulfilled']
+
+    stats = l2.rpc.getroutestats()
+
+    assert [f['status'] for f in stats['forwards']] == ['settled', 'failed', 'offered']

wallet/wallet.c

@@ -2430,3 +2430,63 @@ void wallet_forwarded_payment_add(struct wallet *w, const struct htlc_in *in,
 	sqlite3_bind_int(stmt, 7, state);
 	db_exec_prepared(w->db, stmt);
 }
+
+const struct forwarding_stats *wallet_forwarded_payments_stats(struct wallet *w,
+							      const tal_t *ctx)
+{
+	struct forwarding_stats *stats = talz(ctx, struct forwarding_stats);
+	sqlite3_stmt *stmt;
+	stmt = db_prepare(w->db,
+			  "SELECT"
+			  "  state"
+			  ", COUNT(*)"
+			  ", SUM(out_msatoshi) as total"
+			  ", SUM(in_msatoshi - out_msatoshi) as fee "
+			  "FROM forwarded_payments "
+			  "GROUP BY state;");
+
+	while (sqlite3_step(stmt) == SQLITE_ROW) {
+		enum forward_status state = sqlite3_column_int(stmt, 0);
+		stats->count[state] = sqlite3_column_int64(stmt, 1);
+		stats->msatoshi[state] = sqlite3_column_int64(stmt, 2);
+		stats->fee[state] = sqlite3_column_int64(stmt, 3);
+	}
+
+	db_stmt_done(stmt);
+
+	return stats;
+}
+
+const struct forwarding *wallet_forwarded_payments_get(struct wallet *w,
+						       const tal_t *ctx)
+{
+	struct forwarding *results = tal_arr(ctx, struct forwarding, 0);
+	size_t count = 0;
+	sqlite3_stmt *stmt;
+	stmt = db_prepare(w->db,
+			  "SELECT"
+			  "  f.state"
+			  ", in_msatoshi"
+			  ", out_msatoshi"
+			  ", hin.payment_hash as payment_hash"
+			  ", in_channel_scid"
+			  ", out_channel_scid "
+			  "FROM forwarded_payments f "
+			  "LEFT JOIN channel_htlcs hin ON (f.in_htlc_id == hin.id)");
+
+	for (count=0; sqlite3_step(stmt) == SQLITE_ROW; count++) {
+		tal_resize(&results, count+1);
+		struct forwarding *cur = &results[count];
+		cur->status = sqlite3_column_int(stmt, 0);
+		cur->msatoshi_in = sqlite3_column_int64(stmt, 1);
+		cur->msatoshi_out = sqlite3_column_int64(stmt, 2);
+		cur->fee = cur->msatoshi_in - cur->msatoshi_out;
+		sqlite3_column_sha256_double(stmt, 3, &cur->payment_hash);
+		sqlite3_column_short_channel_id(stmt, 4, &cur->channel_in);
+		sqlite3_column_short_channel_id(stmt, 5, &cur->channel_out);
+	}
+
+	db_stmt_done(stmt);
+
+	return results;
+}

wallet/wallet.h

@@ -146,6 +146,31 @@ static inline enum forward_status wallet_forward_status_in_db(enum forward_statu
 	fatal("%s: %u is invalid", __func__, s);
 }
 
+static inline const char* forward_status_name(enum forward_status status)
+{
+	switch(status) {
+	case FORWARD_OFFERED:
+		return "offered";
+	case FORWARD_SETTLED:
+		return "settled";
+	case FORWARD_FAILED:
+		return "failed";
+	}
+	abort();
+}
+
+struct forwarding {
+	struct short_channel_id channel_in, channel_out;
+	u64 msatoshi_in, msatoshi_out, fee;
+	struct sha256_double payment_hash;
+	enum forward_status status;
+};
+
+struct forwarding_stats {
+	/* One entry for each of the forward_statuses */
+	u64 count[3], msatoshi[3], fee[3];
+};
+
 /* A database backed shachain struct. The datastructure is
  * writethrough, reads are performed from an in-memory version, all
  * writes are passed through to the DB. */
@@ -995,8 +1020,22 @@ u32 *wallet_onchaind_channels(struct wallet *w,
 struct channeltx *wallet_channeltxs_get(struct wallet *w, const tal_t *ctx,
 					u32 channel_id);
 
+/**
+ * Add of update a forwarded_payment
+ */
 void wallet_forwarded_payment_add(struct wallet *w, const struct htlc_in *in,
 				  const struct htlc_out *out,
 				  enum forward_status state);
 
+/**
+ * Retrieve global stats about all forwarded_payments
+ */
+const struct forwarding_stats *wallet_forwarded_payments_stats(struct wallet *w,
+							       const tal_t *ctx);
+
+/**
+ * Retrieve a list of all forwarded_payments
+ */
+const struct forwarding *wallet_forwarded_payments_get(struct wallet *w,
+						       const tal_t *ctx);
 #endif /* LIGHTNING_WALLET_WALLET_H */