txwatch: hand ld to callback, don't assume channel is non-NULL.

We're about to use the txwatch facility for UTXOs, where there's no channel,
so allow that the be NULL, and hand the struct lightningd which callers
want anyway.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

lightningd/onchain_control.c

@@ -75,11 +75,12 @@ static void onchain_tx_depth(struct channel *channel,
 /**
  * Entrypoint for the txwatch callback, calls onchain_tx_depth.
  */
-static enum watch_result onchain_tx_watched(struct channel *channel,
+static enum watch_result onchain_tx_watched(struct lightningd *ld,
+					    struct channel *channel,
 					    const struct bitcoin_txid *txid,
 					    unsigned int depth)
 {
-	u32 blockheight = channel->peer->ld->topology->tip->height;
+	u32 blockheight = get_block_height(ld->topology);
 	if (depth == 0) {
 		log_unusual(channel->log, "Chain reorganization!");
 		channel_set_owner(channel, NULL, false);
@@ -93,7 +94,7 @@ static enum watch_result onchain_tx_watched(struct channel *channel,
 	}
 
 	/* Store the channeltx so we can replay later */
-	wallet_channeltxs_add(channel->peer->ld->wallet, channel,
+	wallet_channeltxs_add(ld->wallet, channel,
 			      WIRE_ONCHAIN_DEPTH, txid, 0, blockheight);
 
 	onchain_tx_depth(channel, txid, depth);

lightningd/peer_control.c

@@ -508,12 +508,12 @@ send_error:
 	peer_start_openingd(peer, &cs, peer_fd, gossip_fd, error);
 }
 
-static enum watch_result funding_lockin_cb(struct channel *channel,
+static enum watch_result funding_lockin_cb(struct lightningd *ld,
+					   struct channel *channel,
 					   const struct bitcoin_txid *txid,
 					   unsigned int depth)
 {
 	const char *txidstr;
-	struct lightningd *ld = channel->peer->ld;
 
 	txidstr = type_to_string(channel, struct bitcoin_txid, txid);
 	log_debug(channel->log, "Funding tx %s depth %u of %u",

lightningd/watch.c

@@ -58,7 +58,7 @@ struct txowatch {
 struct txwatch {
 	struct chain_topology *topo;
 
-	/* Channel who owns us. */
+	/* Channel who owns us (or NULL, for wallet usage). */
 	struct channel *channel;
 
 	/* Transaction to watch. */
@@ -66,7 +66,8 @@ struct txwatch {
 	unsigned int depth;
 
 	/* A new depth (0 if kicked out, otherwise 1 = tip, etc.) */
-	enum watch_result (*cb)(struct channel *channel,
+	enum watch_result (*cb)(struct lightningd *ld,
+				struct channel *channel,
 				const struct bitcoin_txid *txid,
 				unsigned int depth);
 };
@@ -121,9 +122,10 @@ struct txwatch *watch_txid(const tal_t *ctx,
 			   struct chain_topology *topo,
 			   struct channel *channel,
 			   const struct bitcoin_txid *txid,
-			   enum watch_result (*cb)(struct channel *channel,
-						    const struct bitcoin_txid *,
-						    unsigned int depth))
+			   enum watch_result (*cb)(struct lightningd *ld,
+						   struct channel *channel,
+						   const struct bitcoin_txid *,
+						   unsigned int depth))
 {
 	struct txwatch *w;
 
@@ -168,9 +170,10 @@ struct txwatch *watch_tx(const tal_t *ctx,
 			 struct chain_topology *topo,
 			 struct channel *channel,
 			 const struct bitcoin_tx *tx,
-			 enum watch_result (*cb)(struct channel *channel,
-						  const struct bitcoin_txid *,
-						  unsigned int depth))
+			 enum watch_result (*cb)(struct lightningd *ld,
+						 struct channel *channel,
+						 const struct bitcoin_txid *,
+						 unsigned int depth))
 {
 	struct bitcoin_txid txid;
 
@@ -208,15 +211,21 @@ static bool txw_fire(struct txwatch *txw,
 		     unsigned int depth)
 {
 	enum watch_result r;
+	struct log *log;
 
 	if (depth == txw->depth)
 		return false;
-	log_debug(txw->channel->log,
+	if (txw->channel)
+		log = txw->channel->log;
+	else
+		log = txw->topo->log;
+
+	log_debug(log,
 		  "Got depth change %u->%u for %s",
 		  txw->depth, depth,
 		  type_to_string(tmpctx, struct bitcoin_txid, &txw->txid));
 	txw->depth = depth;
-	r = txw->cb(txw->channel, txid, txw->depth);
+	r = txw->cb(txw->topo->bitcoind->ld, txw->channel, txid, txw->depth);
 	switch (r) {
 	case DELETE_WATCH:
 		tal_free(txw);

lightningd/watch.h

@@ -12,6 +12,7 @@ struct bitcoin_tx;
 struct block;
 struct channel;
 struct chain_topology;
+struct lightningd;
 struct txowatch;
 struct txwatch;
 
@@ -43,17 +44,19 @@ struct txwatch *watch_txid(const tal_t *ctx,
 			   struct chain_topology *topo,
 			   struct channel *channel,
 			   const struct bitcoin_txid *txid,
-			   enum watch_result (*cb)(struct channel *channel,
-						    const struct bitcoin_txid *,
+			   enum watch_result (*cb)(struct lightningd *ld,
+						   struct channel *channel,
+						   const struct bitcoin_txid *,
 						   unsigned int depth));
 
 struct txwatch *watch_tx(const tal_t *ctx,
 			 struct chain_topology *topo,
 			 struct channel *channel,
 			 const struct bitcoin_tx *tx,
-			 enum watch_result (*cb)(struct channel *channel,
-						  const struct bitcoin_txid *,
-						  unsigned int depth));
+			 enum watch_result (*cb)(struct lightningd *ld,
+						 struct channel *channel,
+						 const struct bitcoin_txid *,
+						 unsigned int depth));
 
 struct txowatch *watch_txo(const tal_t *ctx,
 			   struct chain_topology *topo,

wallet/test/run-wallet.c

@@ -362,8 +362,9 @@ struct txwatch *watch_txid(const tal_t *ctx UNNEEDED,
 			   struct chain_topology *topo UNNEEDED,
 			   struct channel *channel UNNEEDED,
 			   const struct bitcoin_txid *txid UNNEEDED,
-			   enum watch_result (*cb)(struct channel *channel UNNEEDED,
-						    const struct bitcoin_txid * UNNEEDED,
+			   enum watch_result (*cb)(struct lightningd *ld UNNEEDED,
+						   struct channel *channel UNNEEDED,
+						   const struct bitcoin_txid * UNNEEDED,
 						   unsigned int depth))
 { fprintf(stderr, "watch_txid called!\n"); abort(); }
 /* Generated stub for watch_txo */