topology: Add transaction filtering to connect_block

The filter is being populated while initializing the daemon and by
adding new keys as they are being generated. The filter is then used
in connect_block to identify transactions of interest.

Signed-off-by: Christian Decker <decker.christian@gmail.com>

lightningd/chaintopology.c

@@ -88,8 +88,10 @@ static void connect_block(struct chain_topology *topo,
 		}
 
 		satoshi_owned = 0;
-		wallet_extract_owned_outputs(topo->bitcoind->ld->wallet, tx,
-					     &satoshi_owned);
+		if (txfilter_match(topo->bitcoind->ld->owned_txfilter, tx)) {
+			wallet_extract_owned_outputs(topo->bitcoind->ld->wallet,
+						     tx, &satoshi_owned);
+		}
 
 		/* We did spends first, in case that tells us to watch tx. */
 		bitcoin_txid(tx, &txid);

lightningd/lightningd.c

@@ -213,6 +213,20 @@ struct chainparams *get_chainparams(const struct lightningd *ld)
 			  ld->topology->bitcoind->chainparams);
 }
 
+static void init_txfilter(struct wallet *w, struct txfilter *filter)
+{
+	struct ext_key ext;
+	u64 bip32_max_index;
+
+	bip32_max_index = db_get_intvar(w->db, "bip32_max_index", 0);
+	for (u64 i = 0; i <= bip32_max_index; i++) {
+		if (bip32_key_from_parent(w->bip32_base, i, BIP32_FLAG_KEY_PUBLIC, &ext) != WALLY_OK) {
+			abort();
+		}
+		txfilter_add_derkey(filter, ext.pub_key);
+	}
+}
+
 int main(int argc, char *argv[])
 {
 	struct log_book *log_book;
@@ -253,6 +267,7 @@ int main(int argc, char *argv[])
 
 	/* Initialize wallet, now that we are in the correct directory */
 	ld->wallet = wallet_new(ld, ld->log);
+	ld->owned_txfilter = txfilter_new(ld);
 
 	/* Set up HSM. */
 	hsm_init(ld, newdir);
@@ -260,17 +275,13 @@ int main(int argc, char *argv[])
 	/* Now we know our ID, we can set our color/alias if not already. */
 	setup_color_and_alias(ld);
 
-	/* Initialize block topology (does its own transaction) */
-	setup_topology(ld->topology,
-		       &ld->timers,
-		       ld->config.poll_time,
-		       /* FIXME: Load from peers. */
-		       0);
-
 	/* Everything is within a transaction. */
 	db_begin_transaction(ld->wallet->db);
 
-	/* Load invoices from the database */
+	/* Initialize the transaction filter with our pubkeys. */
+	init_txfilter(ld->wallet, ld->owned_txfilter);
+
+        /* Load invoices from the database */
 	if (!wallet_invoices_load(ld->wallet, ld->invoices)) {
 		fatal("Could not load invoices from the database");
 	}
@@ -298,6 +309,13 @@ int main(int argc, char *argv[])
 
 	db_commit_transaction(ld->wallet->db);
 
+	/* Initialize block topology (does its own transaction) */
+	setup_topology(ld->topology,
+		       &ld->timers,
+		       ld->config.poll_time,
+		       /* FIXME: Load from peers. */
+		       0);
+
 	/* Create RPC socket (if any) */
 	setup_jsonrpc(ld, ld->rpc_filename);
 

lightningd/lightningd.h

@@ -7,6 +7,7 @@
 #include <ccan/time/time.h>
 #include <ccan/timer/timer.h>
 #include <lightningd/htlc_end.h>
+#include <lightningd/txfilter.h>
 #include <stdio.h>
 #include <wallet/wallet.h>
 
@@ -131,6 +132,9 @@ struct lightningd {
 	/* Any outstanding "pay" commands. */
 	struct list_head pay_commands;
 
+	/* Transaction filter matching what we're interested in */
+	struct txfilter *owned_txfilter;
+
 #if DEVELOPER
 	/* If we want to debug a subdaemon. */
 	const char *dev_debug_subdaemon;

lightningd/test/run-find_my_path.c

@@ -13,6 +13,9 @@ void db_begin_transaction_(struct db *db UNNEEDED, const char *location UNNEEDED
 /* Generated stub for db_commit_transaction */
 void db_commit_transaction(struct db *db UNNEEDED)
 { fprintf(stderr, "db_commit_transaction called!\n"); abort(); }
+/* Generated stub for db_get_intvar */
+s64 db_get_intvar(struct db *db UNNEEDED, char *varname UNNEEDED, s64 defval UNNEEDED)
+{ fprintf(stderr, "db_get_intvar called!\n"); abort(); }
 /* Generated stub for debug_poll */
 int debug_poll(struct pollfd *fds UNNEEDED, nfds_t nfds UNNEEDED, int timeout UNNEEDED)
 { fprintf(stderr, "debug_poll called!\n"); abort(); }
@@ -75,6 +78,12 @@ void subd_shutdown(struct subd *subd UNNEEDED, unsigned int seconds UNNEEDED)
 /* Generated stub for timer_expired */
 void timer_expired(tal_t *ctx UNNEEDED, struct timer *timer UNNEEDED)
 { fprintf(stderr, "timer_expired called!\n"); abort(); }
+/* Generated stub for txfilter_add_derkey */
+void txfilter_add_derkey(struct txfilter *filter UNNEEDED, u8 derkey[33])
+{ fprintf(stderr, "txfilter_add_derkey called!\n"); abort(); }
+/* Generated stub for txfilter_new */
+struct txfilter *txfilter_new(const tal_t *ctx UNNEEDED)
+{ fprintf(stderr, "txfilter_new called!\n"); abort(); }
 /* Generated stub for version */
 const char *version(void)
 { fprintf(stderr, "version called!\n"); abort(); }

wallet/walletrpc.c

@@ -222,6 +222,8 @@ static void json_newaddr(struct command *cmd,
 		return;
 	}
 
+	txfilter_add_derkey(cmd->ld->owned_txfilter, ext.pub_key);
+
 	redeemscript = bitcoin_redeem_p2sh_p2wpkh(cmd, &pubkey);
 	sha256(&h, redeemscript, tal_count(redeemscript));
 	ripemd160(&p2sh, h.u.u8, sizeof(h));