closingd: handle our own memleak detection.

Unlike other daemons, closingd doesn't listen to the master, but runs
simply to its own beat.  So instead of responding to the JSON dev_memleak
command, we always check for memory leaks, and make sure that the
python tests fail if they see MEMLEAK in the logs.

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

closingd/closingd.c

@@ -4,6 +4,7 @@
 #include <common/crypto_sync.h>
 #include <common/derive_basepoints.h>
 #include <common/htlc.h>
+#include <common/memleak.h>
 #include <common/peer_billboard.h>
 #include <common/peer_failed.h>
 #include <common/read_peer_msg.h>
@@ -426,6 +427,27 @@ static u64 adjust_offer(struct crypto_state *cs,
 	return (feerange->max + min_fee_to_accept)/2;
 }
 
+#if DEVELOPER
+/* FIXME: We should talk to lightningd anyway, rather than doing this */
+static void closing_dev_memleak(const tal_t *ctx,
+				u8 *scriptpubkey[NUM_SIDES],
+				const u8 *funding_wscript)
+{
+	struct htable *memtable;
+
+	memtable = memleak_enter_allocations(tmpctx,
+					     scriptpubkey[LOCAL],
+					     scriptpubkey[REMOTE]);
+
+	/* Now delete known pointers (these aren't really roots, just
+	 * pointers we know are referenced).*/
+	memleak_remove_referenced(memtable, ctx);
+	memleak_remove_referenced(memtable, funding_wscript);
+
+	dump_memleak(memtable);
+}
+#endif /* DEVELOPER */
+
 int main(int argc, char *argv[])
 {
 	setup_locale();
@@ -490,6 +512,9 @@ int main(int argc, char *argv[])
 			     next_index, revocations_received,
 			     channel_reestablish, final_scriptpubkey);
 
+	/* We don't need this any more */
+	tal_free(final_scriptpubkey);
+
 	peer_billboard(true, "Negotiating closing fee between %"PRIu64
 		       " and %"PRIu64" satoshi (ideal %"PRIu64")",
 		       min_fee_to_accept, commitment_fee, offer[LOCAL]);
@@ -577,6 +602,11 @@ int main(int argc, char *argv[])
 	peer_billboard(true, "We agreed on a closing fee of %"PRIu64" satoshi",
 		       offer[LOCAL]);
 
+#if DEVELOPER
+	/* We don't listen for master commands, so always check memleak here */
+	closing_dev_memleak(ctx, scriptpubkey, funding_wscript);
+#endif
+
 	/* We're done! */
 	/* Properly close the channel first. */
 	if (!socket_close(PEER_FD))

lightningd/peer_control.c

@@ -1455,7 +1455,7 @@ static void peer_memleak_req_next(struct command *cmd, struct channel *prev)
 			if (prev != NULL)
 				continue;
 
-			/* FIXME: handle closingd here */
+			/* Note: closingd does its own checking automatically */
 			if (streq(c->owner->name, "lightning_channeld")) {
 				subd_req(c, c->owner,
 					 take(towire_channel_dev_memleak(NULL)),

tests/fixtures.py

@@ -139,6 +139,11 @@ def node_factory(request, directory, test_name, bitcoind, executor):
     if err_count:
         raise ValueError("{} nodes had bad hsm requests".format(err_count))
 
+    for node in nf.nodes:
+        err_count += checkMemleak(node)
+    if err_count:
+        raise ValueError("{} nodes had memleak messages".format(err_count))
+
     if not ok:
         request.node.has_errors = True
         raise Exception("At least one lightning exited with unexpected non-zero return code")
@@ -212,6 +217,12 @@ def checkBadHSMRequest(node):
     return 0
 
 
+def checkMemleak(node):
+    if node.daemon.is_in_log('MEMLEAK:'):
+        return 1
+    return 0
+
+
 @pytest.fixture
 def executor():
     ex = futures.ThreadPoolExecutor(max_workers=20)