pay: Save nodes and channels used on route to payment.

lightningd/pay.c

@@ -131,6 +131,7 @@ static bool send_payment(struct command *cmd,
 	struct pubkey *ids = tal_arr(tmpctx, struct pubkey, n_hops);
 	struct wallet_payment *payment = NULL;
 	struct htlc_out *hout;
+	struct short_channel_id *channels;
 
 	/* Expiry for HTLCs is absolute.  And add one to give some margin. */
 	base_expiry = get_block_height(cmd->ld->topology) + 1;
@@ -213,6 +214,11 @@ static bool send_payment(struct command *cmd,
 		return false;
 	}
 
+	/* Copy channels used along the route. */
+	channels = tal_arr(tmpctx, struct short_channel_id, n_hops);
+	for (i = 0; i < n_hops; ++i)
+		channels[i] = route[i].channel_id;
+
 	/* If hout fails, payment should be freed too. */
 	payment = tal(hout, struct wallet_payment);
 	payment->id = 0;
@@ -223,6 +229,8 @@ static bool send_payment(struct command *cmd,
 	payment->timestamp = time_now().ts.tv_sec;
 	payment->payment_preimage = NULL;
 	payment->path_secrets = tal_steal(payment, path_secrets);
+	payment->route_nodes = tal_steal(payment, ids);
+	payment->route_channels = tal_steal(payment, channels);
 
 	/* We write this into db when HTLC is actually sent. */
 	wallet_payment_setup(cmd->ld->wallet, payment);

wallet/db.c

@@ -183,6 +183,12 @@ char *dbmigrations[] = {
     "UPDATE invoices"
     "   SET paid_timestamp = strftime('%s', 'now')"
     " WHERE state = 1;",
+    /* We need to keep the route node pubkeys and short channel ids to
+     * correctly mark routing failures. We separate short channel ids
+     * because we cannot safely save them as blobs due to byteorder
+     * concerns. */
+    "ALTER TABLE payments ADD COLUMN route_nodes BLOB;",
+    "ALTER TABLE payments ADD COLUMN route_channels TEXT;",
     NULL,
 };
 
@@ -454,6 +460,86 @@ bool sqlite3_column_short_channel_id(sqlite3_stmt *stmt, int col,
 	size_t sourcelen = sqlite3_column_bytes(stmt, col);
 	return short_channel_id_from_str(source, sourcelen, dest);
 }
+bool sqlite3_bind_short_channel_id_array(sqlite3_stmt *stmt, int col,
+					 const struct short_channel_id *id)
+{
+	const tal_t *tmpctx;
+	char *allser;
+	char *ser;
+	size_t num;
+	size_t i;
+	bool res;
+
+	/* Handle nulls early. */
+	if (!id) {
+		sqlite3_bind_null(stmt, col);
+		return true;
+	}
+
+	tmpctx = tal_tmpctx(id);
+	allser = tal_strdup(tmpctx, "");
+	num = tal_count(id);
+
+	for (i = 0; i < num; ++i) {
+		ser = short_channel_id_to_str(tmpctx, id);
+		if (i == 0)
+			res = tal_append_fmt(&allser, "%s", ser);
+		else
+			res = tal_append_fmt(&allser, ",%s", ser);
+		if (!res) {
+			tal_free(tmpctx);
+			return false;
+		}
+	}
+
+	sqlite3_bind_blob(stmt, col, allser, strlen(allser), SQLITE_TRANSIENT);
+
+	tal_free(tmpctx);
+	return true;
+}
+struct short_channel_id *
+sqlite3_column_short_channel_id_array(const tal_t *ctx,
+				      sqlite3_stmt *stmt, int col)
+{
+	const tal_t *tmpctx;
+	const char *scan;
+	const char *start;
+	const char *end;
+	struct short_channel_id *ret;
+	size_t n;
+
+	/* Handle nulls early. */
+	if (sqlite3_column_type(stmt, col) == SQLITE_NULL)
+		return NULL;
+
+	tmpctx = tal_tmpctx(ctx);
+	scan = sqlite3_column_blob(stmt, col);
+	end = scan + sqlite3_column_bytes(stmt, col);
+	ret = NULL;
+	n = 0;
+
+	/* Scan for comma-separated scid strings. */
+	while (scan != end) {
+		ret = tal_dup_arr (tmpctx, struct short_channel_id,
+				   take(ret), n, 1);
+		if (!ret) {
+			tal_free(tmpctx);
+			return NULL;
+		}
+		start = scan;
+		while (scan != end && *scan != ',')
+			++scan;
+		if (!short_channel_id_from_str(start, scan - start, &ret[n])) {
+			tal_free(tmpctx);
+			return NULL;
+		}
+		++n;
+	}
+
+	ret = tal_steal(ctx, ret);
+	tal_free(tmpctx);
+	return ret;
+}
 
 bool sqlite3_bind_tx(sqlite3_stmt *stmt, int col, const struct bitcoin_tx *tx)
 {
@@ -503,6 +589,60 @@ bool sqlite3_bind_pubkey(sqlite3_stmt *stmt, int col, const struct pubkey *pk)
 	return true;
 }
 
+bool sqlite3_bind_pubkey_array(sqlite3_stmt *stmt, int col,
+			       const struct pubkey *pks)
+{
+	const tal_t *tmpctx;
+	size_t n;
+	size_t i;
+	u8 *ders;
+
+	if (!pks) {
+		sqlite3_bind_null(stmt, col);
+		return true;
+	}
+
+	tmpctx = tal_tmpctx(pks);
+	n = tal_count(pks);
+	ders = tal_arr(tmpctx, u8, n * PUBKEY_DER_LEN);
+
+	for (i = 0; i < n; ++i)
+		pubkey_to_der(&ders[i * PUBKEY_DER_LEN], &pks[i]);
+	sqlite3_bind_blob(stmt, col, ders, tal_len(ders), SQLITE_TRANSIENT);
+
+	tal_free(tmpctx);
+	return true;
+}
+struct pubkey *sqlite3_column_pubkey_array(const tal_t *ctx,
+					   sqlite3_stmt *stmt, int col)
+{
+	const tal_t *tmpctx;
+	size_t i;
+	size_t n;
+	struct pubkey *ret;
+	const u8 *ders;
+
+	if (sqlite3_column_type(stmt, col) == SQLITE_NULL)
+		return NULL;
+
+	tmpctx = tal_tmpctx(ctx);
+	n = sqlite3_column_bytes(stmt, col) / PUBKEY_DER_LEN;
+	assert(n * PUBKEY_DER_LEN == sqlite3_column_bytes(stmt, col));
+	ret = tal_arr(tmpctx, struct pubkey, n);
+	ders = sqlite3_column_blob(stmt, col);
+
+	for (i = 0; i < n; ++i) {
+		if (!pubkey_from_der(&ders[i * PUBKEY_DER_LEN], PUBKEY_DER_LEN, &ret[i])) {
+			tal_free(tmpctx);
+			return NULL;
+		}
+	}
+
+	ret = tal_steal(ctx, ret);
+	tal_free(tmpctx);
+	return ret;
+}
+
 bool sqlite3_column_preimage(sqlite3_stmt *stmt, int col,  struct preimage *dest)
 {
 	assert(sqlite3_column_bytes(stmt, col) == sizeof(struct preimage));

wallet/db.h

@@ -117,6 +117,11 @@ bool sqlite3_bind_short_channel_id(sqlite3_stmt *stmt, int col,
 				   const struct short_channel_id *id);
 bool sqlite3_column_short_channel_id(sqlite3_stmt *stmt, int col,
 				     struct short_channel_id *dest);
+bool sqlite3_bind_short_channel_id_array(sqlite3_stmt *stmt, int col,
+					 const struct short_channel_id *id);
+struct short_channel_id *
+sqlite3_column_short_channel_id_array(const tal_t *ctx,
+				      sqlite3_stmt *stmt, int col);
 bool sqlite3_bind_tx(sqlite3_stmt *stmt, int col, const struct bitcoin_tx *tx);
 struct bitcoin_tx *sqlite3_column_tx(const tal_t *ctx, sqlite3_stmt *stmt,
 				     int col);
@@ -126,6 +131,11 @@ bool sqlite3_column_signature(sqlite3_stmt *stmt, int col, secp256k1_ecdsa_signa
 bool sqlite3_column_pubkey(sqlite3_stmt *stmt, int col,  struct pubkey *dest);
 bool sqlite3_bind_pubkey(sqlite3_stmt *stmt, int col, const struct pubkey *pk);
 
+bool sqlite3_bind_pubkey_array(sqlite3_stmt *stmt, int col,
+			       const struct pubkey *pks);
+struct pubkey *sqlite3_column_pubkey_array(const tal_t *ctx,
+					   sqlite3_stmt *stmt, int col);
+
 bool sqlite3_column_preimage(sqlite3_stmt *stmt, int col,  struct preimage *dest);
 bool sqlite3_bind_preimage(sqlite3_stmt *stmt, int col, const struct preimage *p);
 

wallet/wallet.c

@@ -1288,8 +1288,10 @@ void wallet_payment_store(struct wallet *wallet,
 		"  destination,"
 		"  msatoshi,"
 		"  timestamp,"
-		"  path_secrets"
-		") VALUES (?, ?, ?, ?, ?, ?);");
+		"  path_secrets,"
+		"  route_nodes,"
+		"  route_channels"
+		") VALUES (?, ?, ?, ?, ?, ?, ?, ?);");
 
 	sqlite3_bind_int(stmt, 1, payment->status);
 	sqlite3_bind_sha256(stmt, 2, &payment->payment_hash);
@@ -1299,6 +1301,9 @@ void wallet_payment_store(struct wallet *wallet,
 	sqlite3_bind_blob(stmt, 6, payment->path_secrets,
 				   tal_len(payment->path_secrets),
 				   SQLITE_TRANSIENT);
+	sqlite3_bind_pubkey_array(stmt, 7, payment->route_nodes);
+	sqlite3_bind_short_channel_id_array(stmt, 8,
+					    payment->route_channels);
 
 	db_exec_prepared(wallet->db, stmt);
 
@@ -1346,6 +1351,11 @@ static struct wallet_payment *wallet_stmt2payment(const tal_t *ctx,
 
 	/* Can be NULL for old db! */
 	payment->path_secrets = sqlite3_column_secrets(payment, stmt, 7);
+
+	payment->route_nodes = sqlite3_column_pubkey_array(payment, stmt, 8);
+	payment->route_channels
+		= sqlite3_column_short_channel_id_array(payment, stmt, 9);
+
 	return payment;
 }
 
@@ -1364,7 +1374,7 @@ wallet_payment_by_hash(const tal_t *ctx, struct wallet *wallet,
 	stmt = db_prepare(wallet->db,
 			  "SELECT id, status, destination,"
 			  "msatoshi, payment_hash, timestamp, payment_preimage, "
-			  "path_secrets "
+			  "path_secrets, route_nodes, route_channels "
 			  "FROM payments "
 			  "WHERE payment_hash = ?");
 
@@ -1456,7 +1466,7 @@ wallet_payment_list(const tal_t *ctx,
 			wallet->db,
 			"SELECT id, status, destination, "
 			"msatoshi, payment_hash, timestamp, payment_preimage, "
-			"path_secrets "
+			"path_secrets, route_nodes, route_channels "
 			"FROM payments;");
 	}
 

wallet/wallet.h

@@ -93,7 +93,10 @@ struct wallet_payment {
 	u64 msatoshi;
 	/* Iff PAYMENT_COMPLETE */
 	struct preimage *payment_preimage;
+	/* Needed for recovering from routing failures. */
 	struct secret *path_secrets;
+	struct pubkey *route_nodes;
+	struct short_channel_id *route_channels;
 };
 
 /**